Macro to Collapse pivot rows which don't have subrows?

Hi there,

I've got a 3-level hierachy (Customer - Category - Product). Could someone please help to write a macro which will collapse any Categories which don't have Products (as highlighted in yellow below)?

I think best explained by the screenshot . Sample book attached. I'd really appreciate any help. I've tried for a good two hours in order to do this but I'm chasing my tail.

screenshot.png

Best wishes,
Michelle