Open4 and security

We are trying to implement Open4 and have only the users that report to a supervisor be seen by that particular supervisor. For example the CEO can see everyone when logged in, the VP of Engineering can see everyone below him, the manager of engineering can see everyone below him, etc. Has anyone set this up to be this way - I was originally told that to do that you have to setup different departments to achieve this but did stumble across something called use position security.