How many layers of nested mental states can humans track?

Are we sure this is not a limitation of language and language capabilities?

First off, I found toddlers can quite well understand some concepts or tasks, but struggle to understand your intent when you merely tell them instead of showing them.

Personally, I would struggle with these nested mental states if they were merely said to me. If I however was allowed to make a diagram, I suspect I’d have far less issues with them