layer masks not working independently

I have a document where the background and subject are on separate layers ("BACKGROUND" and "COLUMN").  In the 1st screenshot, I have a portion of the column selected.  In the 2nd, I have it copied to its own layer.  The adjustments to the column are now not showing because of the intervening layer.  In the 3rd screen shot, I have moved the selection layer to the top of the stack.  However, now all the adjutsments to the background layer are deactivated.  I don't understand why this is happening.  Can anyone help?  Thanks.