$filter
apply_filters( $filter, '<a href="' . $link . '">' . $text . '</a>', (int)$total_items )
API Hooks: BuddyPress:: File: bp-groupsbp-groups-activity-php (3)
groups_register_activity_actions
do_action( 'groups_register_activity_actions' )
groups_format_notifications
do_action( 'groups_format_notifications', $action, $item_id, $secondary_item_id, $total_items )