Inconsistent Mapping Requirements Within Data Set

Hi, I need to find a way to simply map data from a table to a series of reports. Normally, this would be accomplishable through a simple SUMIFS, but the requirement is a bit more complicated. I want to create two reports. One for Business A and one for Business B.

Attached is a file containing a data set, mapping table and two example reports.

If a VLOOKUP or INDEX/MATCH are used to look up the Business into the data tab using Group, Group 1 will only associate with Business A and not Business B, since the lookup will find and pull the first value.

Note that the data set and mapping tables that are being used in reality are very large and change often. The above is an example. The issue being highlighted occurs several times within the mapping table / report requirements. As such, I'm trying to keep the file size limited and the model dynamic, so a solution which duplicates the data within the data set and requires entering a static index number next to each row is not ideal.

Are there any thoughts on a simple system to map the data into the reports given these requirements?

Thanks!