Each bar is wrapped in cellophane, which are then wrapped in the normal outer packaging. To make the 4 pack, they simply took 2x two packs and put them on a cardboard tray,and then wrapped those.
I don’t think I’ve ever gone through so much unwrapping for candy.
Many things didn’t used to be packaged at all, they were sold loose in bulk. The shop would put them in a paper bag at purchase.