CMS Made Simple Forums

It would be useful to be able to create sub sites within a site i.e. to have it's own menu hierarchy. I would have thought the way to do this would be able to create categories and then when creating a page assign it to a specific category. This is nothing to do whether or not a user is logged in.

If this can already be done using the MenuManger please forgive me as I am a newbie to CMSMS just let me know if it can be done this way.