Show activities of defined BuddyPress groups [closed]

After getting all the groups_ids i get all activities_ids by doing:

<?php
    global $bp,$wpdb;
    $groups_ids = implode(', ', $groups_ids);
    $sql = "SELECT id FROM {$bp->activity->table_name} WHERE component="groups" AND item_id IN ({$groups_ids})";
    $activity_ids = $wpdb->get_results( $sql);
    $a_id = array();
    foreach ($activity_ids as $activity_id )
    {
        $a_id[] = $activity_id->id;
    }
?>  

Then i get only one activity loop with the specified groups by doing:

$params = array('per_page' => '6',  'in' => $a_id);

if ( bp_has_activities($params) )   :
endif;