Sorry, I should have been more specific.
You do have to go to the advanced restore settings and select "restore a backup from a different computer". That will take you to a screen where you choose a device that's directly connected, or a network share.
Again, the restore program will only look at the root directory of a device that's directly connected.
So, even if an external device is directly connected, you still have to share it and then access it through the network share.
Hope this helps !!!