Movies Anywhere and more than one Apple ID?

How does Movies Anywhere work with multiple Apple IDs? For example, I have a couple of Apple IDs that I've used in the past for purchasing movies. Can I link them to the same Movies Anywhere account, or somehow combine the movies bought via those two Apple IDs (an age-old question I think)?

A similar question applies to Family Sharing. If members of my family have purchased movies under different Apple IDs, can they be linked to a single Movies Anywhere account?