I'm not familiar with this out of the box. However perhaps there is a creative way to do this by using custom code. Let's say you passed in a custom mbox parameter on each page like level1 level2 level3 etc you could then create audiences based on that and report on those audiences. Just a thought. Hope it helps.
If this satisfies your query please like, mark as helpful and mark as answer. Otherwise lets keep the conversation going. Hope you have a wonderful day.
Hi christophert87757717 Adding to what Mihnea suggested , you fire an mbox as they scroll a certain amount down the page and use that as a metric . You could also leverage A4T in your target activity as analytics has those metrics.