/** * PIT - Nav Menu CSS Class * - Add "current-menu-item" on the archive link when we are on a "singular" */ add_filter('nav_menu_css_class' , '_pit_menu_item_css_class_singular' , 10, 4); function _pit_menu_item_css_class_singular($classes, $item, $args, $depth) { $menu_item_type = $item->type; if ($menu_item_type !== 'post_type_archive') return $classes; $post_type = $item->object; if (!is_singular($post_type)) return $classes; $classes[] = 'current-menu-item'; return $classes; }