I realised when playing around with filters that there were some inconsistencies with how they worked, so I’ve just normalised them all, and added a brand new filter.
Now, all the Character-related fillers (Doctors, Companions, Villains, Real-Life Characters) work as “OR” filters. Here’s the difference:
When selecting multiple characters, for example Daleks and Cybermen:
- An “OR” filter shows all stories where there are Daleks, OR Cybermen, OR both.
- An “AND” filter would only show stories where there are Daleks AND Cybermen.
If you want to narrow down stories to only those with BOTH of these characters, you’ll need to use the brand new filter called “Characters (AND)”.
This is a copy of the Characters filter, but selecting multiple characters is only possible if they all exist in the same story.
If in doubt, check the tooltip I’ve added to every character-related filter, which explains how that filter works:
I hope this makes sense 
it should make finding stories easier!