mypmpro-custom-billing-fields-geocode.php

<?php
/**
 * This recipe will use custom billing fields and geocode them instead of default
 * fields during the checkout process.
 *
 * Check for the $_REQUEST variable first before checking for the stored user meta.
 *
 * You can add this recipe to your site by creating a custom plugin
 * or using the Code Snippets plugin available for free in the WordPress repository.
 * Read this companion article for step-by-step directions on either method.
 * https://www.paidmembershipspro.com/create-a-plugin-for-pmpro-customizations/
 */
function mypmpromm_custom_address_fields( $member_address, $user_id, $morder ){

	$member_address = array(
		'street' =>  '',
		'city' => ( !empty( $_REQUEST['city'] ) ) ? $_REQUEST['city'] : get_user_meta( $user_id, 'city', true ),
		'zip' => ( !empty( $_REQUEST['zip_code'] ) ) ? $_REQUEST['zip_code'] : get_user_meta( $user_id, 'zip_code', true ),
		'country' => '',
	);

	return $member_address;
}
add_filter( 'pmpromm_member_address_after_checkout', 'mypmpromm_custom_address_fields', 10, 3 );