Tree structure drop-down?

Hi all,

I am trying to build a report-like spreadsheet simply to convey key stats.

What would be ideal is if I could add a drop-down tree to hide/show sub data. I.e. when someone hits the little "+" on the left of a cell, a sub-dataset is displayed (and contracted upon another click).

Please see the attached sheet .. if that helps or not..

Hopefully I've posed the question coherently enough!

Thanks as always!

TD

Never mind, I found the feature I wanted called "Group" .