I guess you’ll see for yourself, but after they lose the armour, Luke keeps the belt over his desert gear. Presumably for the sole reason that he’d have a grappling hook to swing later, but you can justify it as the farmboy finding all the gadgets pretty neat. That said, Han keeps his too:
Though it seems only Luke’s stormtrooper belt had the hook in the first place. Here’s the same guy before getting jumped:
