Changing target directory for Norton 360 Backup

I'm backing up multiple machines to a network (NAS) drive.  Norton 360 wants to back everything up to the root directory of the target drive.  How can I change the target directory so that each machine backs up to a separate subdirectory on the same network drive?

On each system you will need to map a different folder as a drive.

(Rather than mapping the drive, map a folder)

Dave