Hi.
I just had the same question, and googling for it brought me here.
I solved it prett easily:
- Open two explorer Windows
- Navigate to your NAS in both windows using the Network Path (NOT the mapped drive); Usually \\[NameofyourNAS]
- Further navigate to the source folder in one window and the target folder in the other window
- CTRL-X (Cut) the files/folders from the source folder
- CTRL-V (Paste) the files/folder in the source folder
Couple of seconds later: Everything's done.