The difference between QTP and TestComplete when it comes to the hierarchy may be the model used in calling web page objects. I'm not certain, but I think that either Hybrid or Tree model are used by default when TestComplete is originally installed. I don't know QTP very well at all but, judging from the code you've posted, I suspect that QTP uses more of a DOM model where the hierarchy is "hidden" by simply identifying the different items on a page simply as a list of page objects rather than embedded objects within other objects.
See the following article to learn more about these models.
http://smartbear.com/support/viewarticle/12439/
