If you want to see the next level of any item listed on the BOM screen,
you can move down to that Item and Press Enter, and then select the
BOM button from that IN-A screen.

Kevin,
 
Actually I don't think it is that simple (I wish it was) - you can't just click on the part number.  You would think it should work that way, but instead you have to highlight the part, click the green drill down button, click Inventory, then hit enter and then push the BOM button again.  (too many steps!!)
 
Even Colin's suggestion really isn't that different.  You have to F2, type in the item #, drill down button,  click on BOM  (OK, 4 steps, slightly better), but I still can't see the entire BOM.  (helpful when you have a lot of structure)
 
It is still simpler for me just to print out an indented BOM where I can see everything.  It would be nice to have that come up graphically, from the IN-A screen.

Allen,
 
I understand.  Put it on the wish list.  

Yeah, the Classic menu works the way you mentioned, but for some reason, the EVO menu doesn't let you just hit enter when you have the part highlighted.
 
Anyway, the indented Graphical BOM is on my wish list.