Filter custom post type by taxonomy

filter_cpt_by_taxonomies.php

<?php
/**
 * Adds admin area filtering for CPT taxonomies.
 *
 * @param string $post_type The post type slug.
 * @return void
 */
function filter_cpt_by_taxonomies( $post_type ) {

	// Apply this only on a specific post type
	if ( 'example_post_type' !== $post_type ) {
		return;
	}

	// A list of taxonomy slugs to filter by
	$taxonomies = array( 'article-categories', 'article-authors', 'locations', );

	foreach ( $taxonomies as $taxonomy_slug ) {

		$params = array(
			'show_option_all' => get_taxonomy($taxonomy_slug)->labels->all_items,
			'hide_empty' => true,
			'hierarchical' => 1,
			'show_count' => true,
			'orderby' => 'name',
			'name' => $taxonomy_slug,
			'value_field' => 'slug',
			'taxonomy' => $taxonomy_slug,
		);

		if ( isset($_GET[$taxonomy_slug]) ) {
			$params['selected'] = $_GET[$taxonomy_slug]; // choose selected taxonomy by $_GET variable
		}
		
		wp_dropdown_categories($params);
	}

}
add_action( 'restrict_manage_posts', 'filter_cpt_by_taxonomies' );