Remove all Node Descendants when remove Node parent in MongoDB

[napoleon211092]

I have read your example. It's very helpful for me.
In my practices, I want to remove Node parent means delete all Node Descendants.

For example:

When I remove "Cell_Phones_and_Accessories" node, it must remove Cell_Phones_and_Smartphones, Headset, Battery, Cables_And_Adapter, Nokia, Samsung, HTC, Apple and Vyacheslav

I am referring to the Tree Structure with Parent Reference.
Please help me.