1. open the Timeline, A Catholic Dictionary, and The HarperCollins Bible Dictionary (Revised and Updated).
2. Set Timeline to Follow mode

3. Click on an event in one of the dictionaries ... you should get something that moves one or more events from the resource to the top of the Timeline and shows the resource being followed.

4: BUG: subsequent clicks on events which should come under "Follow" in either dictionary result in only a quick circle indicating the location of the event ... which may or may not be visible. I would expect the behavior to match that of the first occurrence.
5. Note: scrolling within a resource results in follow working as I expecting ... events appearing above the book title. But I can't get Follow to switch to the other dictionary ....
This may be a lack of knowledge on my part as to how this is supposed to work but ...