It sounds like you are looking for a client that will limit the user to only their home directory and the subdirectories thereof, however, this is not something that should be handled client side. An FTP client will request any folder the user wants, and there is no way to force users to only use a specific client. It is up to the server to reject the request if the user is attempting to visit something outside of their home folder. This is usually set in the configuration file for your specific FTP server application. If it helps, many FTP servers follow a similar configuration setup to that of Apache.

__________________
The best way to learn anything, is to question everything.
Interestingly Average Security Blog