It seems to me that you need a higher level here. There should only be a single "Root". In this case you are trying to have two different roots. I may be wrong but it seems that thinking of a Hierarchy lilke a single tree with many branches, you must have a single root or essentially have different trees all together (separate table structure). The two organizations that you are trying to make as the root, I assume that they correlate somehow to one overarching "organization"? If so that should be the single root, and each of the two that you have now as the root should be the second level of the Hierarchy.