Dear Adriano,
1. I was wondering whether you still have the solution to this saved somewhere? I was unable to complete the project at the time but have now been called to continue.
2. Also, do you – or anyone – know if this is still the best solution to achieve the desired bottom level/top level effect. Here's my original question: http://wp-types.com/forums/topic/bottom-level-posts-listed-inside-related-top-level-posts-possible/#post-94013
Apologies if I should have started a new thread.