It's pretty difficult to explain, check out this image to see what I'm working with. I feel this h

So basically I'm trying to create the effect that these two letters are laid over each over, like this. I've made two white letters, and what I did was give them two different patterns(they have transparent backgrounds) in the blending options. But because the actual letter is white, they don't overlap how I'd like. Basically, I'd like the white sections of the letter to be transparent, but I don't know how. If anyone knows how to do this I'd be very happy.

I'd appreciate any help, thanks in advance.