LaCie 1 TB drive not showing encrypted backups

Hi everyone. I bought a LaCie 1 TB HD from the Apple store about 4 months ago. I've done a few backups on it since, which has eaten up over half of the drive. When I open the drive, it looks empty/I can't see any files. I'd like to clear up more space on this drive. How do I visualize and remove the encrypted files or anything else that's eating up room on this drive?