Creating Bill Of Material From Single Table

I would like to create Bill of material from single table. I need to select multiple parameters, to expend it till the lowest level, so I will try to explain:

I have one table (ODBC) and there's all data we need. Parent number col A, Item number col B and quantity col C. First level I select main Item number A1234 (this is only thing that I should choose, everything else should be automatically), I get table with all items that are parent A1234 (let's say 10 items). Now I need to look again one level lower in same table for items that have Parent item in list of those 10 items listed earlier (let's say 30 items) and multiply their quantities with quantity of their Parent Item (total qty could be in column D). Then one level lower for items with parent items in those 30 and so on and so on. So when I choose main Item I would like to get table like below (take notice that real table has over a 100.000 items, but I want to show only Bill of material for the main item till the lowest level).

Parent Item
Item
QTY
Total QTY

A1234
B1111
5

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I'm flexible and ok to use VBA, SQL, Excel functions, multiple tables (how to select multiple parameters??)