That sounds trivial I think because you are looking for exactly one item and there's no pagination involved.

The problem might be to get those 352nd pages of every book with the title starting with "A" sitting on 3rd shelf of every city library: when there are unbounded results nested deeper than top-level, and possibly those multiple times, that's when it gets hairy.

Actually, it's about opening 10 different books at different pages and similarly upwards... There is no GraphQL mechanism for it outside some hack in individual libraries that does more server roundtrips, and it seems like GraphQL authors simply avoid discussing it.

How would you implement this with rest / something more traditional?

For example, you can make a separate REST method returning all levels you need. However, it still doesn't account for items lost while paginating (e.g. some visible items are deleted while one scrolls on a device etc.).