Bitmask Help

I could do this but it doesnt quite fill what Im trying to achieve, I want to allow the user to filter the option of spawned meshes, so with the bitmask you can tick A,B,C and leave D unticked. Now the blueprint will only try to randomly spawn a,b or c and ignore D entirely. It can be done with bools and branches, but bitmasks seemed tidier and Id like to learn them.