How to Change the BuddyPress User Query with SQL | http://ibenic.com/change-buddypress-user-query-sql

sql.php

<?php

add_filter( 'bp_user_query_uid_clauses', 'filtering_memberpress', 10, 2 );

/**
* Filtering only users with an active memebership
* @param $sql array
* @param $query BP_User_Query
* @return array
*/
function filtering_memberpress( $sql, $query ) {
    
    // MemberPress is Active
    if( class_exists( 'MeprDb' ) ) {
        // Get the MemberPress members database object
        $mepr_db = new MeprDb();
        // Add a JOIN to the select
        $sql['select'] .= ' LEFT JOIN ' . $mepr_db->members . ' as members on members.user_id = u.' . $query->uid_name . ' ';
        // Add a WHERE clause
        $sql['where'][] = " members.memberships != ''";
    }
    return $sql;
}