To my knowledge, it does not go down more than 1 level. 

I hope Acumatica is addressing this.  Lets look at an example of how it works at the moment:

Sales order that has rows for the following:

• Stock items that are purchased
  Does not work so if you have insufficient stock for a purchase item you have no idea when it can be in stock
   
• Items with single level BOMs
  The only rows where you can get a reliable result
   
• Items that have multi-level BOMs that are assemble to order
  If you have stock of the subassembly then you are OK.  The whole idea of ATO is to reduce time to delivery.  But if insufficient stock of the subassembly then it Errors.
   
• Items that are multi-level make to order.
  Fails if there is insufficient stock of any subassembly

So CTP fails 75% of the time.