Displaying BOMs Level by Level 
Use
You use this function if you want to display the components for every assembly in the multi-level BOM for a sales order item.
Prerequisites
On the screen BOM level by level: View (see
Extending the View for BOM Explosion) the multi-level indicator must be set.
Procedure
The BOM Level by Level: Initial Screen appears.

On the initial screen you do not have to enter a material number. In multi-level order BOM explosions, the whole bill of material (from the material in the sales order item) is always displayed. If you are interested in a particular assembly from an extensive bill of material, it can help to enter the material number of the header material for this assembly on the initial screen. You can then see the assembly on the screen straight away without having to scroll.
selecting a BOM if necessary.
For the required quantity the system automatically proposes the order quantity from the sales document. This value can not be changed here.
and enter the selection criteria for BOM explosion.
. Result
You see a list of all items that fulfill your selection criteria. The quantities refer to the required quantity displayed in the list header.

An assembly is not exploded under certain circumstances.
When is a BOM Explosion Terminated?