How to join query datasource to EITHER its sister datasource OR its parent?

I am attempting to join a query datasource to Either its parent OR its sister, but am not getting the desired results.

I overrode the init method of the query and added a range to the subject datasource with a query expression after the super() similar to this:

datasourceRange.value('((whsLoadLine.inventTransId == salesLine.inventTransId) || (whsLoadLine.inventTransId == kitSalesLine.inventTransId))');

SalesLine = Parent DS

    kitSalesLine = Child of SalesLine

    whsLoadLine = Child of SalesLine

The issue is that it is not returning whsLoadLine records for the kitSalesLines.

At this point, my assumption is that this just isn't possible.   I can't make the whsLoadLine a child of the KitSalesLine because it would change the formatting of the XML.  This is an aif document query.