Comment by Telaneo

This has happened to me twice in Norway and once in Germany, but only with large groups of people, so it's never 'normally'. If you're a smaller group or alone, the waiter will either remember who had what (or have kept track in their POS system?), or outright ask who will pay for what, since there are so few items to pay for that that's pretty manageable.

The more common way to settle this in my experience, if you're in a larger group, is to announce your intention to split the bill before ordering, and then the waiter can go through what groups or individuals will pay and can track them accordingly.