Advanced Multi-Level Parent Summation (BOM type)

I have a followup to my original thread with a new request for help with a more complex calculation, hence the new thread. I can't post a link to the original thread, but it was called "Multi-Level Parent Summation (BOM Type).

What I am looking to do now is add a sumproduct into the rollup array. In the attached workbook, column A represents the levels of a Bill of Materials (BOM), Column B and Column C are two associated values that need to be multiplied together to calculate the Parent Sum. Column D shows manual calculations for the Parent Sum. The tricky part seems to be that a Parent rollup will itself have to be multipled by the "Multiplier" (column C), in order for the total parent rollup to be correct. End goal is one formula in Column D that can be copied down, that will grab the appropriate child values from columns B and C and create a total Parent value for each line item. Thanks so much!