add_action( 'init', 'listing_search_url' );
  function listing_search_url()
  {
    add_rewrite_tag('%type%', '([^&]+)');
    add_rewrite_tag('%search_location%', '([^&]+)');
    add_rewrite_rule(
        '^custom(/([^/]+))?/(/([^/]+))?/?',
        'index.php?page_id=23&type=$matches[2]&search_location=$matches[4]',
        'top'
    );
    flush_rewrite_rules();
  }