Invert a hierarchy

I am trying to build a P&L reports in WEBI using a BICS connection. BW provides the hierarchy which is around the wrong way. I need a way to invert the hierarchy for my reporting.

Current Hierarchy (example)

Net Profit after Tax

--> Gross margin

--> Sales

--> COGS

Output Required (example)

Sales

COGS

--> Gross Margin

--> Net Profit after Tax

Is there a way to invert the hierarchy in BEx or WEBI? Or to add an index in BW?

One, not ideal, solution

I have thought of using an excel datasource that can provide an index and then merge dimensions in Webi. This is messy.