Just create destination mtree as NetWorker device, mark it as read only device. NetWorker supports mapping one volume to more devices, so it will read label and use the tape.

Regards

Lukas

I am assuming the Data Domain Devices you mentioned are DDBoost devices. then the steps are like follow.

1. In the target Data Domain need to convert/modify the MTree to a Storage Unit so can be accessed by NetWorker as DDBoost Device and assign the same user to own the Storage unit. For example, if in the primary data Domain DDBoost user is "boostuser" and user ID is 500, then in the target DD the Storage unit has to be owned by the user whose user ID is 500
2. Mount the device from target DD from NetWorker using modified device access path
3. That's it, run the restore

Hope this help