Hi,
I guess, just like you would access the NAS share on the Prod, same applies for Vault/Mirror.
As long as CIFS is configured on the Vault/Mirror SVM:
1) Just mount the destination 'vault/mirror' Volume into the 'Namespace'
2) Once it is available in the Namespace, you should be able to go to 'shares' and click 'create share'.
3) Enable snapdir-access
::> volume modify -vserver <vserver> -volume <vault_mirror> -snapdir-access true
4) Now, you should be able to go to folder | click 'previous version' and restore the files.
Thanks!