subtract a workpath selection from a larger workpath

my job prohibits me sharing images if needed can make quick sketch if can't question across clear enough.

 

here have.

 

the image stack of objects , have made work path of objects (one large selection labeled "all" around objects isolate away background), have work path of bottom object (labeled "bottom").

 

my goal.

 

i quite often, i'd able subtract "bottom" work path selection larger "all" work path selection.

 

thanks

 

p.s. tried faq , search before posting.

sorry, i'm idiot. adding layers , deleting , selecting works. have sworn there way subtract 1 selection if there please chime in.

More discussions in Photoshop Macintosh (read only)

adobe