Make Indented BOM into Flat BOM

Hello Everyone,

I have been struggling with this problem for years and would greatly appreciate any support. Solidworks exports indented BOM's in the following parent child format.

1 - Top most Parent
1.1 - first child of parent
1.1.1 - child of first child
2 - second most parent
2.1 - first child of second parent
..
..
..
etc

I have provided a simple example below:

Number Item QTY
1 Truck 1
1.1 wheel 4
1.1.1 rim 3
2 axel 2
2.1 brake 4
2.1.1 brake fluid 6
3 window 1
4 Seat 1

I want to find the QTY of items it takes to make the Truck. The answer is below

ANSWER
Truck 1
wheel 4
rim 12
axel 2
brake 8
brake fluid 48
window 1
Seat 1

How would you go about solving this for larger BOM's?