Whenever I go to create a new custom chart these days I end up discovering that what I want isn't possible. Very often, I want to combine different tags when creating a chart.

Example:
How many of the books I've read have a female main character (tag 1) written by a male (tag 2) vs. female author (tag 3) compared to male main character (tag 4) written by a male (tag 2) vs. female author (tag 3).

I'd like this to be a bar chart with these 4 bars:
tag 1 + tag 2
tag 1 + tag 3
tag 4 + tag 2
tag 4 + tag 3

(Ideally I'd then also love to compare this with rating information, e.g. to see which of the four combinations I rate highest (so a bar showing the number of books for each combination that have a rating higher than 3), but that would probably make it too complicated because it would be basically two charts in one).