Parent/Child With SUMX

I have multiple tables that have parent/child relationships within them. I have created PATH column in each one of them and created a measure to be able to see the summed up value for the nodes as per here.

But I have a header table that can link several of the companies and label them lets say east or west in this example. I would like to see the sum of whole east node that consist of Company A and Company C. Here is the Power BI file for reference.

Here is the screenshot of tables and output I need. The top section contains incoming tables. Bottom left is summation within the first table as described in the forum link above. Bottom right is the table that I need but without Company Column in there and only one row for East/West.

Output I want to see: East 1050; West 600

Note in my modelling I won't be able to connect the Headers table to Sales table as in my real problem I have Sales table at the center surrounded with multiple Master Data with Parent/Child hierarchy in each Master Data. One Header table can not be connected to all the Master Data tables that are filtering one central Key Figure table.