This topic is dear to my heart, as we recently migrated all our Jive SBS training materials over to Jivespace:
Not sure if this is the exact use case you're describing, but check out how I used private groups for each training course, and linked to those groups from within a formatted text widget on the Education space's home page. The user training course is an open group, as that's a freebie, but the others are private groups.
The result is that content posted to the private group only shows up in Recent Content for people who are members in that group.