As for that, you can sub-class CCLayer and call it “ItemButton” or something and put some CCSprite, CCLabel, and CCMenuItemImage that when tapped, the layer is expanded downwards showing the description of the item. You then create a bunch of these objects and put them in your layer. You might also need to resize the layer when an “ItemButton” object is tapped.
I’m not really sure as I’m just saying what’s on top of my head. Try playing around with CCObjects. The way I see it, it’s pretty simple to do.