[doudda]

Sorry, if this has an answer already but my limited skills searching this forum weren't fruitful.

For ex. I have this categories and sub-categories:

Favorites
__Crime
__Romance
__Thriller
Crime
__Historic
__Futuristic
Romance
Thriller

How can I make the books in Favorites.Crime show also in Crime, or better yet Crime.Historic?
Is that even possible?

Thanks in advance for your attention.