My example is for a theatre. I want to list all of the artists in a show, as well as any and all characters they play in that show. I thought I would simply utilize a couple of multi-reference fields in my Artists collection.
Characters collection: reference all characters that an artist plays across ALL shows (which also reference the Shows collection)
Well, I can filter my initial collection list of artists to just those in the current show. However, I can't filter my nested collection list of characters to just the characters in the current show.
Sure, it is probably more straightforward to attack in the reverse—list the characters which reference the single artist that plays each character. But it would be nice to have the first option of filtering a nested collection list (which follows the info precedent set by the likes of an IMDB).