How do I make it so multiple walls in a sheet metal part unfold as one piece? (CATIA v5)

I have a sheet metal part. (It is really a flat flex cable that I am drawing using the sheet metal tool.) Both ends of the cable have a special shape so I drew them as seperate walls. When I use the flattened view or unfold feature the second wall does not unfold with the rest of the part. All of the features are under one body. I tried using a positioned sketch for the second wall, but it did not work.