add_filter( 'the_comments', 'my_the_comments', 10, 2 );

function my_the_comments( $results, &$comment_query ) {
    global $current_user;

    if ( !is_admin() ) {
        if ( isset( $current_user ) && ( $current_user instanceof WP_User ) ) {
            if ( is_array( $results ) ) {
                foreach ( $results as $key=>$comment ) {
                    $post_id = $comment->comment_post_ID;
                    $user_id = $current_user->ID;
                    if ( !Groups_Post_Access::user_can_read_post( $post_id, $user_id ) ) {
                        unset( $results[$key] );
                    }

                }
            }
        }
    }
    return $results;
}