$filter
apply_filters( $filter, '<a href="' . $link . '">' . $text . '</a>', (int)$total_items )
apply_filters( $filter, '<a href="' . $link . '">' . $text . '</a>', (int)$total_items )
do_action( 'groups_register_activity_actions' )
do_action( 'groups_format_notifications', $action, $item_id, $secondary_item_id, $total_items )