Add all users in a buddypress group

Add all users in a buddypress group.php

<?php
/*
* Needs php greatet than 5.3
*
* (not for all, written for special purpose)
*/

add_action('load-users.php',function() {

	if(isset($_GET['action']) && isset($_GET['bp_gid']) && isset($_GET['users'])) {
    		$group_id = $_GET['bp_gid'];
    		$users = $_GET['users'];
    		foreach ($users as $user_id) {
        		groups_join_group( $group_id, $user_id );
    		}
	}
});