How to create a dynamic parent child hierarchy workflow

[YellowDuck15]

I have a workflow that is joining data from two in-db connections, doing some cleanup of the values, and then resulting in the data in rows 1-6 below.  I need to find a way to create the Parent/Child hierarchy in rows 9-29 based on this data.

A few things to note:

1) In the screen shot below, in the first 6 rows, column A rolls up to B, B rolls up to C, C to D, etc.

2) [NULL] values should be skipped so that the child rolls up to the next available parent.

3) The underlying data may change occasionally, resulting in new rows (i.e. new Plants) and/or [NULL] values filled in.

4) The very top value of the hierarchy (Business Units) is created in the workflow.

5) For anyone familiar, this is creating a dimension hierarchy for load into Hyperion ASO (I left off the Alias and Properties columns for this question).

My first attempt was to basically create separate paths for each parent/child pair (e.g. one for Segment to Company, one for Division to Segment, etc.) and then union the results together, but this creates a problem when there are [NULL] values (not to mention, there has to be a better way).  I thought something like an iterative macro would work, but all the examples I found had the macro starting at the very beginning and not half way through the workflow.

Thanks in advance!