how to give each bitmap layer its own adjustment layer?

I have a photo made up of 3 layers of bitmaps.
How can I add one adjustment layer to each of the three bitmaps that would
affect only that bitmap and not the other two?

I first tried putting one bitmap into a layer set and then added an
adjustment layer in that layset set. Still, that adjustment layer affects
all layers below :-(

This is photoshop 6, BTW.