multiple nfs shares with cinder-backup

Hello all! I'm currently using openstack queens with cinder 12.0.10. I would like to a backend I'm using a NFS-share. Now i would like to spit my backups up to two nfs-shares. I have seen that the cinder.volume.driver can handle multiple nfs shares. But it seems that cinder.backup.driver can not. Is there a way to use two nfs shares for backups? Or is it maybe possible with a later release of Cinder? regards, MaSch