function check_custom_post_type( $can_access, $user_id, $post_id ) {

    if ( 'test' == get_post_type( $post_id ) ) {

        $client_id = get_field( 'client_name', $post_id );

        if ( $user_id != $client_id ) {
            $can_access = false;
        }

    }

    return $can_access;

}

add_filter( 'wpf_user_can_access', 'check_custom_post_type', 10, 3 );