Is there an easier way to search for crossovers.

I used to use an unofficial app for ao3. I know its not supported in the community but it was easier to use it than the site.

One of reasons was the ability limit the amount of fandom tags. Ao3 is FILLED with these massive crossover stories and the app helped filtering those out by allowing you to place a limit on how many fandoms could be tagged in a fic.

There were other things but this was the main reason. Is there a work around so that I can start using the main site?