Hani,
You can't nest AAs in B-ACD. After all, it is a 'basic' ACD.
What you can do is originally send the call to a CUE AA for the parent prompt, and then based on that option, redirect to a BACD AA for the child prompt. Something like this:
8000--->CUE AA. Press 1----->redirect to BACD AA x8010
8000--->CUE AA. Press 2----->redirect to BACD AA x8011
There is a sample config on the BACD configuration guide that shows how you can have multiple BACD AAs on a single system. Note that when you do that, you still only configure a single call queue.
-Steve