The CLI has ability to do a snapvault restore but this really only makes sense if it is NFS, remember in snapvault the qtree is restored or recovered.
Otherwise you can clone the snapvault volume. SImply make a new config which points at snapvault volume and use the mount / umount options in CLI
If this is NFS easiest thing is just mount the secondary volume to do restore.
SC 3.6 will have mount and umount options in GUI but there will be no snapvault restore interface in GUI in 3.6 either, maybe 4.0...most people simply dont do snapvault restores, they either mount or clone to do restore of secondary.
Here is example of snapvault restore interface in CLI: