Populating the part numbers based on Level numbers in multi level BoM

Hello

Based on the column A `Level number' part numbers to be plotted as shown in the light yellow columns D:E as results by formulas.

Note :
* Level `0' part numbers will usually more than one and different part numbers, but here only one `0' part number available.
* In Light yellow cells results need to be produced for all cells but shown only for some cells for illustration purpose which is also intermittent.

Thanks in advance

Sekar