Re-roll of https://www.drupal.org/project/address/issues/2626982#comment-15382818 to apply on 2.0.2 . This would not be required once we started to use 2.1.x releases.

preferred_countries-2626982-55-rerolled-for-2.0.2.patch

diff --git a/config/schema/address.schema.yml b/config/schema/address.schema.yml
index e706c72..a9643b8 100644
--- a/config/schema/address.schema.yml
+++ b/config/schema/address.schema.yml
@@ -151,6 +151,11 @@ field.widget.settings.address_default:
     wrapper_type:
       type: string
       label: Wrapper type
+    preferred_countries:
+      type: sequence
+      label: 'Preferred countries'
+      sequence:
+        type: string
 
 field.widget.settings.address_zone_default:
   type: mapping
@@ -183,6 +188,12 @@ views.field.subdivision:
 views.filter.country:
   type: views.filter.in_operator
   label: 'Country'
+  mapping:
+    preferred_countries:
+      type: sequence
+      label: 'Preferred countries'
+      sequence:
+        type: string
 
 views.filter.country_code:
   type: views.filter.country
diff --git a/src/Element/Address.php b/src/Element/Address.php
index 9d68f3c..ae4e9d8 100644
--- a/src/Element/Address.php
+++ b/src/Element/Address.php
@@ -43,6 +43,7 @@ use Drupal\Core\Render\Element\FormElement;
  *     AddressField::POSTAL_CODE => FieldOverride::OPTIONAL,
  *   ],
  *   '#available_countries' => ['DE', 'FR'],
+ *   '#preferred_countries' => ['DE'],
  * ];
  * @endcode
  *
@@ -60,6 +61,8 @@ class Address extends FormElement {
       '#available_countries' => [],
       // FieldOverride constants keyed by AddressField constants.
       '#field_overrides' => [],
+      // List of country codes. Listed countries will be at the top of select.
+      '#preferred_countries' => [],
 
       '#input' => TRUE,
       '#multiple' => FALSE,
@@ -177,6 +180,7 @@ class Address extends FormElement {
       '#type' => 'address_country',
       '#title' => t('Country'),
       '#available_countries' => $element['#available_countries'],
+      '#preferred_countries' => $element['#preferred_countries'],
       '#default_value' => $element['#default_value']['country_code'],
       '#required' => $element['#required'],
       '#limit_validation_errors' => [],
diff --git a/src/Element/Country.php b/src/Element/Country.php
index 145f46f..96d85a4 100644
--- a/src/Element/Country.php
+++ b/src/Element/Country.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\address\Element;
 
+use Drupal\address\PreferredCountriesTrait;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Render\Element\FormElement;
 
@@ -14,6 +15,7 @@ use Drupal\Core\Render\Element\FormElement;
  *   '#type' => 'address_country',
  *   '#default_value' => 'DE',
  *   '#available_countries' => ['DE', 'FR'],
+ *   '#preferred_countries' => ['DE'],
  * ];
  * @endcode
  *
@@ -21,6 +23,8 @@ use Drupal\Core\Render\Element\FormElement;
  */
 class Country extends FormElement {
 
+  use PreferredCountriesTrait;
+
   /**
    * {@inheritdoc}
    */
@@ -29,6 +33,8 @@ class Country extends FormElement {
     return [
       // List of country codes. If empty, all countries will be available.
       '#available_countries' => [],
+      // List of country codes. Listed countries will be at the top of select.
+      '#preferred_countries' => [],
 
       '#input' => TRUE,
       '#multiple' => FALSE,
@@ -81,6 +87,14 @@ class Country extends FormElement {
     }
 
     $element['#tree'] = TRUE;
+
+    // Rebuild country options if any preferred countries have been selected.
+    $preferred_countries = $element['#preferred_countries'] ?? [];
+    $preferred_countries = array_combine($preferred_countries, $preferred_countries);
+    $country_options = empty($preferred_countries)
+      ? $country_list
+      : self::rebuildCountryList($country_list, $preferred_countries);
+
     // Hide the dropdown when there is only one possible value.
     if (count($country_list) == 1 && $element['#required']) {
       $element['country_code'] = [
@@ -94,7 +108,7 @@ class Country extends FormElement {
         '#title' => $element['#title'],
         '#title_display' => $element['#title_display'],
         '#description_display' => $element['#description_display'],
-        '#options' => $country_list,
+        '#options' => $country_options,
         '#default_value' => $element['#default_value'],
         '#required' => $element['#required'],
         '#disabled' => $element['#disabled'],
diff --git a/src/Plugin/Field/FieldWidget/AddressDefaultWidget.php b/src/Plugin/Field/FieldWidget/AddressDefaultWidget.php
index 7cc303d..dfe2149 100644
--- a/src/Plugin/Field/FieldWidget/AddressDefaultWidget.php
+++ b/src/Plugin/Field/FieldWidget/AddressDefaultWidget.php
@@ -94,11 +94,12 @@ class AddressDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
     );
   }
 
-  /**
+   /**
    * {@inheritdoc}
    */
   public static function defaultSettings() {
     return [
+      'preferred_countries' => [],
       'wrapper_type' => 'fieldset',
     ] + parent::defaultSettings();
   }
@@ -107,14 +108,32 @@ class AddressDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
    * {@inheritdoc}
    */
   public function settingsForm(array $form, FormStateInterface $form_state) {
-    return [
-      'wrapper_type' => [
-        '#type' => 'radios',
-        '#title' => $this->t('Wrapper type'),
-        '#options' => $this->wrapperTypeOptions(),
-        '#default_value' => $this->getSetting('wrapper_type'),
-      ],
+    $element = [];
+
+    $country_list = $this->countryRepository->getList();
+    $available_countries = $this->getFieldSetting('available_countries');
+    if (!empty($available_countries)) {
+      $country_list = array_intersect_key($country_list, $available_countries);
+    }
+
+    $element['preferred_countries'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Preferred countries'),
+      '#options' => $country_list,
+      '#default_value' => $this->getSetting('preferred_countries'),
+      '#empty_value' => '',
+      '#multiple' => TRUE,
+      '#size' => 10,
+    ];
+
+    $element['wrapper_type'] = [
+      '#type' => 'radios',
+      '#title' => $this->t('Wrapper type'),
+      '#options' => $this->wrapperTypeOptions(),
+      '#default_value' => $this->getSetting('wrapper_type'),
     ];
+
+    return $element;
   }
 
   /**
@@ -122,9 +141,26 @@ class AddressDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
    */
   public function settingsSummary() {
     $summary = parent::settingsSummary();
+
+    // Add summary for preferred countries setting.
+    $preferred_countries = $this->getSetting('preferred_countries');
+    if (!empty($preferred_countries)) {
+        $country_list = $this->countryRepository->getList();
+        foreach ($preferred_countries as &$preferred_country) {
+            $preferred_country = $country_list[$preferred_country];
+        }
+        $summary[] = $this->formatPlural(count($preferred_countries),
+            'Preferred country: @countries',
+            'Preferred countries: @countries',
+            ['@countries' => implode(', ', $preferred_countries)]
+        );
+    }
+
+    // Add summary for wrapper type setting.
     $summary[] = $this->t('Wrapper type: @wrapper_type', [
       '@wrapper_type' => $this->wrapperTypeOptions()[$this->getSetting('wrapper_type')],
     ]);
+
     return $summary;
   }
 
@@ -170,6 +206,7 @@ class AddressDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
       '#required' => $required,
       '#available_countries' => $item->getAvailableCountries(),
       '#field_overrides' => $item->getFieldOverrides(),
+      '#preferred_countries' => $this->getSetting('preferred_countries'),
     ];
     // Make sure no properties are required on the default value widget.
     if ($this->isDefaultValueWidget($form_state)) {
diff --git a/src/Plugin/Field/FieldWidget/CountryDefaultWidget.php b/src/Plugin/Field/FieldWidget/CountryDefaultWidget.php
index 6a2b1e3..ff0152f 100644
--- a/src/Plugin/Field/FieldWidget/CountryDefaultWidget.php
+++ b/src/Plugin/Field/FieldWidget/CountryDefaultWidget.php
@@ -68,6 +68,65 @@ class CountryDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
     );
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return [
+      'preferred_countries' => [],
+    ] + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, FormStateInterface $form_state) {
+    $element = [];
+
+    $country_list = $this->countryRepository->getList();
+    $available_countries = $this->getFieldSetting('available_countries');
+    if (!empty($available_countries)) {
+      $country_list = array_intersect_key($country_list, $available_countries);
+    }
+
+    $element['preferred_countries'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Preferred countries'),
+      '#options' => $country_list,
+      '#default_value' => $this->getSetting('preferred_countries'),
+      '#empty_value' => '',
+      '#multiple' => TRUE,
+      '#size' => 10,
+    ];
+
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = [];
+
+    // Display summary for preferred countries setting.
+    $preferred_countries = $this->getSetting('preferred_countries');
+    if (!empty($preferred_countries)) {
+      if (!isset($country_list)) {
+        $country_list = $this->countryRepository->getList();
+      }
+      foreach ($preferred_countries as &$preferred_country) {
+        $preferred_country = $country_list[$preferred_country];
+      }
+      $summary['preferred_countries'] = $this->formatPlural(count($preferred_countries),
+        'Preferred country: @countries',
+        'Preferred countries: @countries',
+        ['@countries' => implode(', ', $preferred_countries)]
+      );
+    }
+
+    return $summary;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -76,6 +135,7 @@ class CountryDefaultWidget extends WidgetBase implements ContainerFactoryPluginI
       '#type' => 'address_country',
       '#default_value' => $items[$delta]->value,
       '#available_countries' => $items[$delta]->getAvailableCountries(),
+      '#preferred_countries' => $this->getSetting('preferred_countries'),
     ] + $element;
 
     return $element;
diff --git a/src/Plugin/views/filter/Country.php b/src/Plugin/views/filter/Country.php
index 2462f97..13f0f7d 100644
--- a/src/Plugin/views/filter/Country.php
+++ b/src/Plugin/views/filter/Country.php
@@ -2,6 +2,9 @@
 
 namespace Drupal\address\Plugin\views\filter;
 
+use Drupal\address\PreferredCountriesTrait;
+use Drupal\Core\Form\FormStateInterface;
+
 /**
  * Filter by country.
  *
@@ -11,6 +14,8 @@ namespace Drupal\address\Plugin\views\filter;
  */
 class Country extends CountryAwareInOperatorBase {
 
+  use PreferredCountriesTrait;
+
   /**
    * {@inheritdoc}
    */
@@ -22,4 +27,50 @@ class Country extends CountryAwareInOperatorBase {
     return $this->valueOptions;
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function buildExposedForm(&$form, FormStateInterface $form_state) {
+    parent::buildExposedForm($form, $form_state);
+
+    // We're implementing preferred_countries and the optgroup support only here
+    // in the exposed filter select, so as not to break the admin UI default
+    // value form's checkboxes, which don't handle nested arrays properly.
+    $preferred_countries = $this->options['preferred_countries'];
+    if (!empty($preferred_countries)) {
+      $form_key = $this->options['expose']['identifier'];
+      $form[$form_key]['#options'] = self::rebuildCountryList($form[$form_key]['#options'], $preferred_countries);
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function defineOptions() {
+    $options = parent::defineOptions();
+    $options['preferred_countries'] = ['default' => []];
+    return $options;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildOptionsForm(&$form, FormStateInterface $form_state) {
+    parent::buildOptionsForm($form, $form_state);
+    $form['preferred_countries'] = [
+      '#type' => 'select',
+      '#title' => $this->t('Preferred countries'),
+      '#options' => $this->getAvailableCountries(),
+      '#multiple' => TRUE,
+      '#default_value' => $this->options['preferred_countries'],
+      '#states' => [
+        'visible' => [
+          ':input[name="options[expose_button][checkbox][checkbox]"]' => [
+            'checked' => TRUE,
+          ],
+        ],
+      ],
+    ];
+  }
+
 }
diff --git a/src/PreferredCountriesTrait.php b/src/PreferredCountriesTrait.php
new file mode 100644
index 0000000..058635d
--- /dev/null
+++ b/src/PreferredCountriesTrait.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Drupal\address;
+
+use Drupal\Core\StringTranslation\TranslatableMarkup;
+
+/**
+ * Provides a trait for handling preferred countries.
+ */
+trait PreferredCountriesTrait {
+
+  /**
+   * Rebuilds a given country list to provide for select '#options'.
+   *
+   * Takes preferred countries and a possible "All" value into account,
+   * grouping all non-preferred countries in an "Other" optgroup.
+   *
+   * @var string[] $country_list
+   *   Associative array of available countries, keyed by country code, with
+   *   the values being translated country names, already sorted alphabetically
+   *   by country name.
+   * @var string[] $preferred_candidates
+   *   Associative array of preferred countries, keyed by country code. The
+   *   values don't matter. These are only candidates, as they need to appear
+   *   in the $country_list as well.
+   *
+   * @return string[]
+   *   Array of country options, with preferred candidates going first in list.
+   */
+  public static function rebuildCountryList($country_list, $preferred_candidates) {
+    // See if there really are preferred countries.
+    $preferred_countries = array_intersect_key($country_list, $preferred_candidates);
+    if (empty($preferred_countries)) {
+      return $country_list;
+    }
+
+    // Start afresh, prepending the 'All' element, if present.
+    $country_options = [];
+    if (!empty($country_list['All'])) {
+      $country_options += [
+        'All' => $country_list['All'],
+      ];
+      unset($country_list['All']);
+    }
+
+    // Add 'Preferred countries' and purge from the input list.
+    $country_options += $preferred_countries;
+    foreach (array_keys($preferred_countries) as $country_code) {
+      unset($country_list[$country_code]);
+    }
+
+    // Render all other options, if any, in an 'Other' optgroup.
+    if (!empty($country_list)) {
+      $other_label = (string) new TranslatableMarkup('Other');
+      $country_options += [
+        $other_label => $country_list,
+      ];
+    }
+    return $country_options;
+  }
+
+}
diff --git a/tests/modules/address_test/config/install/core.entity_form_display.node.address_test.default.yml b/tests/modules/address_test/config/install/core.entity_form_display.node.address_test.default.yml
new file mode 100644
index 0000000..cf5936d
--- /dev/null
+++ b/tests/modules/address_test/config/install/core.entity_form_display.node.address_test.default.yml
@@ -0,0 +1,65 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - field.field.node.address_test.field_address_test
+    - node.type.address_test
+  module:
+    - address
+id: node.address_test.default
+targetEntityType: node
+bundle: address_test
+mode: default
+content:
+  created:
+    type: datetime_timestamp
+    weight: 2
+    region: content
+    settings: {  }
+    third_party_settings: {  }
+  field_address_test:
+    type: address_default
+    weight: 7
+    region: content
+    settings: {  }
+    third_party_settings: {  }
+  promote:
+    type: boolean_checkbox
+    weight: 3
+    region: content
+    settings:
+      display_label: true
+    third_party_settings: {  }
+  status:
+    type: boolean_checkbox
+    weight: 6
+    region: content
+    settings:
+      display_label: true
+    third_party_settings: {  }
+  sticky:
+    type: boolean_checkbox
+    weight: 4
+    region: content
+    settings:
+      display_label: true
+    third_party_settings: {  }
+  title:
+    type: string_textfield
+    weight: 0
+    region: content
+    settings:
+      size: 60
+      placeholder: ''
+    third_party_settings: {  }
+  uid:
+    type: entity_reference_autocomplete
+    weight: 1
+    region: content
+    settings:
+      match_operator: CONTAINS
+      match_limit: 10
+      size: 60
+      placeholder: ''
+    third_party_settings: {  }
+hidden: {  }
diff --git a/tests/modules/address_test/config/optional/views.view.address_test_preferred_countries.yml b/tests/modules/address_test/config/optional/views.view.address_test_preferred_countries.yml
new file mode 100644
index 0000000..aab8ecc
--- /dev/null
+++ b/tests/modules/address_test/config/optional/views.view.address_test_preferred_countries.yml
@@ -0,0 +1,224 @@
+langcode: en
+status: true
+dependencies:
+  config:
+    - node.type.address_test
+  module:
+    - address
+    - node
+    - user
+id: address_test_preferred_countries
+label: 'Address test preferred countries'
+module: views
+description: ''
+tag: ''
+base_table: node_field_data
+base_field: nid
+display:
+  default:
+    id: default
+    display_title: Default
+    display_plugin: default
+    position: 0
+    display_options:
+      title: 'Address test preferred countries'
+      fields:
+        title:
+          id: title
+          table: node_field_data
+          field: title
+          relationship: none
+          group_type: group
+          admin_label: ''
+          entity_type: node
+          entity_field: title
+          plugin_id: field
+          label: ''
+          exclude: false
+          alter:
+            alter_text: false
+            make_link: false
+            absolute: false
+            word_boundary: false
+            ellipsis: false
+            strip_tags: false
+            trim: false
+            html: false
+          element_type: ''
+          element_class: ''
+          element_label_type: ''
+          element_label_class: ''
+          element_label_colon: true
+          element_wrapper_type: ''
+          element_wrapper_class: ''
+          element_default_classes: true
+          empty: ''
+          hide_empty: false
+          empty_zero: false
+          hide_alter_empty: true
+          click_sort_column: value
+          type: string
+          settings:
+            link_to_entity: true
+          group_column: value
+          group_columns: {  }
+          group_rows: true
+          delta_limit: 0
+          delta_offset: 0
+          delta_reversed: false
+          delta_first_last: false
+          multi_type: separator
+          separator: ', '
+          field_api_classes: false
+      pager:
+        type: mini
+        options:
+          offset: 0
+          items_per_page: 10
+          total_pages: null
+          id: 0
+          tags:
+            next: ››
+            previous: ‹‹
+          expose:
+            items_per_page: false
+            items_per_page_label: 'Items per page'
+            items_per_page_options: '5, 10, 25, 50'
+            items_per_page_options_all: false
+            items_per_page_options_all_label: '- All -'
+            offset: false
+            offset_label: Offset
+      exposed_form:
+        type: basic
+        options:
+          submit_button: Apply
+          reset_button: false
+          reset_button_label: Reset
+          exposed_sorts_label: 'Sort by'
+          expose_sort_order: true
+          sort_asc_label: Asc
+          sort_desc_label: Desc
+      access:
+        type: perm
+        options:
+          perm: 'access content'
+      cache:
+        type: tag
+        options: {  }
+      empty: {  }
+      sorts: {  }
+      arguments: {  }
+      filters:
+        status:
+          id: status
+          table: node_field_data
+          field: status
+          entity_type: node
+          entity_field: status
+          plugin_id: boolean
+          value: '1'
+          group: 1
+          expose:
+            operator: ''
+            operator_limit_selection: false
+            operator_list: {  }
+        type:
+          id: type
+          table: node_field_data
+          field: type
+          entity_type: node
+          entity_field: type
+          plugin_id: bundle
+          value:
+            address_test: address_test
+          expose:
+            operator_limit_selection: false
+            operator_list: {  }
+        field_address_test_country_code:
+          id: field_address_test_country_code
+          table: node__field_address_test
+          field: field_address_test_country_code
+          relationship: none
+          group_type: group
+          admin_label: ''
+          plugin_id: country
+          operator: in
+          value: {  }
+          group: 1
+          exposed: true
+          expose:
+            operator_id: field_address_test_country_code_op
+            label: 'Address (field_address_test:country_code)'
+            description: ''
+            use_operator: false
+            operator: field_address_test_country_code_op
+            operator_limit_selection: false
+            operator_list: {  }
+            identifier: field_address_test_country_code
+            required: false
+            remember: false
+            multiple: false
+            remember_roles:
+              authenticated: authenticated
+              anonymous: '0'
+              content_editor: '0'
+              administrator: '0'
+              test_new_role: '0'
+            reduce: false
+          is_grouped: false
+          group_info:
+            label: ''
+            description: ''
+            identifier: ''
+            optional: true
+            widget: select
+            multiple: false
+            remember: false
+            default_group: All
+            default_group_multiple: {  }
+            group_items: {  }
+          preferred_countries: {  }
+      style:
+        type: default
+      row:
+        type: fields
+      query:
+        type: views_query
+        options:
+          query_comment: ''
+          disable_sql_rewrite: false
+          distinct: false
+          replica: false
+          query_tags: {  }
+      relationships: {  }
+      header: {  }
+      footer: {  }
+      display_extenders: {  }
+    cache_metadata:
+      max-age: -1
+      contexts:
+          - 'languages:language_content'
+          - 'languages:language_interface'
+          - url
+          - url.query_args
+          - 'user.node_grants:view'
+          - user.permissions
+      tags: {  }
+  page_1:
+    id: page_1
+    display_title: Page
+    display_plugin: page
+    position: 1
+    display_options:
+      display_extenders: {  }
+      path: address-test/views/preferred-countries
+    cache_metadata:
+      max-age: -1
+      contexts:
+          - 'languages:language_content'
+          - 'languages:language_interface'
+          - url
+          - url.query_args
+          - 'user.node_grants:view'
+          - user.permissions
+      tags: {  }
diff --git a/tests/src/FunctionalJavascript/AddressPreferredCountriesTest.php b/tests/src/FunctionalJavascript/AddressPreferredCountriesTest.php
new file mode 100644
index 0000000..4712e56
--- /dev/null
+++ b/tests/src/FunctionalJavascript/AddressPreferredCountriesTest.php
@@ -0,0 +1,100 @@
+<?php
+
+namespace Drupal\Tests\address\FunctionalJavascript;
+
+use Drupal\FunctionalJavascriptTests\WebDriverTestBase;
+use Drupal\views\Views;
+
+/**
+ * Tests the preferred countries settings.
+ *
+ * @group address
+ */
+class AddressPreferredCountriesTest extends WebDriverTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected static $modules = [
+    'address',
+    'address_test',
+    'node',
+    'views',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected $defaultTheme = 'stark';
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->drupalLogin($this->drupalCreateUser([
+      'access content',
+      'create address_test content',
+    ]));
+  }
+
+  /**
+   * Tests the preferred countries setting for country exposed filter.
+   */
+  public function testViewsPreferredCountriesExposedSetting() {
+    // Set up views filter configuration.
+    $view = Views::getView('address_test_preferred_countries');
+    $filters = $view->getDisplay()->getOption('filters');
+    $filters['field_address_test_country_code']['preferred_countries'] = [
+      'CA' => 'CA',
+      'GB' => 'GB',
+      'US' => 'US',
+    ];
+    $view->getDisplay()->overrideOption('filters', $filters);
+    $view->save();
+
+    // Go to views page with exposed filters and confirm filter exists.
+    $this->drupalGet('address-test/views/preferred-countries');
+    $this->assertSession()->elementExists('xpath', '//select[@name="field_address_test_country_code"]');
+
+    // Make sure configured preferred countries are displayed first.
+    $elements = $this->xpath('//select[@name="field_address_test_country_code"]/option');
+    $preferred_options = [];
+    foreach ($elements as $element) {
+      if ($option = $element->getValue()) {
+        $preferred_options[] = $option;
+      }
+    }
+    $this->assertEquals(['All', 'CA', 'GB', 'US'], $preferred_options, 'Preferred countries are not displayed first in the exposed filter select.');
+  }
+
+  /**
+   * Tests the preferred countries setting for widget.
+   */
+  public function testWidgetPreferredCountriesSetting() {
+    // Adjust widget settings to have preferred countries.
+    $display = \Drupal::configFactory()
+      ->getEditable('core.entity_form_display.node.address_test.default');
+    $display->set('content.field_address_test.settings.preferred_countries', [
+      'CA',
+      'GB',
+      'US',
+    ])->save();
+
+    // Go to node add page and confirm field exists.
+    $this->drupalGet('node/add/address_test');
+    $this->assertSession()->elementExists('xpath', '//select[@name="field_address_test[0][address][country_code]"]');
+
+    // Make sure configured preferred countries are displayed first.
+    $elements = $this->xpath('//select[@name="field_address_test[0][address][country_code]"]/option');
+    $preferred_options = [];
+    foreach ($elements as $element) {
+      if ($option = $element->getValue()) {
+        $preferred_options[] = $option;
+      }
+    }
+    $this->assertEquals(['CA', 'GB', 'US'], $preferred_options, 'Preferred countries are not displayed first in the exposed filter select.');
+  }
+
+}