/**
 * Returns all users with a specific level.
 *
 * @param string $level_name Paid Membershp Pro level name.
 *
 * @return array
 */
function mpp_custom_get_pmpro_users_with_level_name( string $level_name ): array {
    global $wpdb;

    // make sure pmpro is enabled.
    if ( ! function_exists( 'pmpro_getAllLevels' ) ) {
        return array();
    }

    $user_ids = $wpdb->get_col(
        $wpdb->prepare(
            "SELECT mu.user_id FROM {$wpdb->pmpro_membership_levels} AS l
            JOIN {$wpdb->pmpro_memberships_users} AS mu ON (l.id = mu.membership_id)
                                    WHERE mu.status = 'active' AND l.name=%s", $level_name
        ) );

    return array_map( 'absint', $user_ids );
}

/**
 * Exclude users with the specific level from directory.
 */
add_filter( 'mpp_main_gallery_query_args', function ( $args ) {

    // not the directory page.
    if ( ! empty( $args['component'] ) ) {
        return $args;
    }

    // CHANGE this line.
    $level_name            = "Basic";
    $args['exclude_users'] = mpp_custom_get_pmpro_users_with_level_name( $level_name );

    return $args;
} );