Hello Erin,
Unfortunately, this functionality isn't provided in the current version of Kentico CMS. Actually there is a relation 1:1.
On the other side, if you want functionality like this available in the feature version of Kentico, you can suggest it and also other users will be able to vote for it (more users = higher priority), on the special page:
UserVoice.
Best Regards,
Martin Danko