tar -zxf /backups/filename.tar.gz /home/theboss
I think this will give you /home/theboss/home/theboss/..., won't it? I believe that you need to run the extraction from the root directory used for creation of the tar file. IOW, if you were actually IN /home/theboss when you ran tar, then, yes, go to /home/theboss. But, your tar won't actually have anything in it starting with /home/theboss, will it?
If this was a full backup, cd to "/". You can do a sort of trial run by running the following and seeing the full pathnames of what's in tar, if you don't already know.
oops, deleted see edit below
You can also go to some temporary directory and run your extract to see what gets created under that temp directory.
Sorry, that should be:
tar -ztvf /backups/filename.tar.gz /home/theboss