mypmpro-sortable-country-memberlist.php

<?php //do not copy

/**
 * This recipe adds a sortable column to the member list. 
 * 
 * This assumes that a 'country' User Field has been created. 
 * 
 * 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 mypmpro_custom_sortable_memberlist_col( $columns ) {

    $columns["pmpro_bcountry"] = "Country";
    return $columns;

}
add_filter('manage_memberships_page_pmpro-memberslist_columns', 'mypmpro_custom_sortable_memberlist_col');
add_filter('manage_memberships_page_pmpro-memberslist_sortable_columns', 'mypmpro_custom_sortable_memberlist_col');

function mypmpro_country_column( $colname, $user_id ) {
	
	if ( $colname == 'pmpro_bcountry'){
		
		$country = get_user_meta( $user_id, 'pmpro_bcountry', true );

		if( empty( $country ) ) {
			echo " - ";
		} else {
			echo $country;
		}
		
		
	}
	
}
add_action('pmpro_manage_memberslist_custom_column', 'mypmpro_country_column', 10, 2);

function mypmpro_sortable_country_col( $query ) {

	global $wpdb;

	if( ! empty( $_REQUEST['only'] ) ) {
		$country = "AND umh.meta_value = '".sanitize_text_field( $_REQUEST['only'] )."' ";
	} else {
		$country = '';
	}
	
	//Change pmpro_bcountry to the relevant field name
	$query = str_replace( "WHERE mu.membership_id > 0  AND mu.status = 'active'", "LEFT JOIN $wpdb->usermeta umh ON umh.meta_key = 'pmpro_bcountry' AND u.ID = umh.user_id WHERE mu.membership_id > 0  AND mu.status = 'active' ".$country, $query );

	return $query;

}
add_filter( 'pmpro_members_list_sql', 'mypmpro_sortable_country_col', 10, 1 );

function mypmro_allowed_country_orderby( $allowed ) {

	$allowed['Country'] = 'umh.meta_value';

	return $allowed;

}
add_filter( 'pmpro_memberslist_allowed_orderbys', 'mypmro_allowed_country_orderby', 10, 1 );

Here's a partner recipe to create a dropdown select for countries on the memberslist page - https://gist.github.com/ipokkel/5731b00b3be9c49ba2ee642216b5765c