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

    if ( function_exists( 'rcp_user_can_access' ) && ! ​rcp_user_can_access( $user_id, $post_id ) ) {
        return false;
    }

    return $can_access;

}

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