Как да направим нов филтър в WordPress администрацията по custom taxonomy и в custom post type

add_action('restrict_manage_posts','my_restrict_manage_posts');

function my_restrict_manage_posts() {
			global $typenow;

			if ($typenow=='job_listing'){
                         $args = array(
                             'show_option_all' => "Show All Cities",
                             'taxonomy'        => 'listing_cities',
                             'name'               => 'listing_cities'

                         );
				wp_dropdown_categories($args);
                        }
		}
add_action( 'request', 'my_request' );
function my_request($request) {
	if (is_admin() && $GLOBALS['PHP_SELF'] == '/wp-admin/edit.php' && isset($request['post_type']) && $request['post_type']=='job_listing') {
		$request['listing_cities'] = get_term($request['listing_cities'],'listing_cities')->name;
	}
	return $request;
}