Assign subfolder as The highest directory level for a certain user?

Hi

After installing the WD mybook live NAS Server, and activate it as an FTP Server. The control panel is very basic and not comprehensive enough. I want to creat a new user, assign a certain path for it. which I need it to be a subfolder in the main root of the hard drive.

Meaning, that this use will have this directory path as the highest directory level when brwosing the FTP Server.

So Can I change the root path for indvidual users ?

Thanks

No, at least trough the UI 

Not sure if possible via SSH