can i mask a part of a layer ?

[voozel]

this is one of my major issues lol i am horrible at masking and dont get i. anyway my question is can i mask one part of a layer ?
like when i try to make a character cross arms ..i always have the problem with the arm layer behind the body..i dont know how to get it to be behind and on top of the body
and so i dont have to make another Topic ..i cant use the "follow path" tool on a bone layer and all of my character are mainly bone layers ..so is there a way to use it on a bone layer or should i do something else to move my character

[slowtiger]

The parts you want to mask must be on their separate layer. Masking works only layer-wise.