[Owncloud] SFTP to a user's ownCloud files?

[Advrk Aplmrkt]

Hello,

Is it possible to setup my RHEL based server running ownCloud so that
an ownCloud user can SFTP into their ownCloud WebDAV share and
upload/download files?

My server already has SSH service setup, but:

(1) Can it be done so that when the ownCloud user SFTP in, they can
only see their ownCloud files, and not the rest of the system!

(2) How do I actually do this?

Thanks!