Nested Tabs on ZEN component

Hi

I'm starting to play around with dynamically creating tabs and panes from query data, and was trying to do the following, with nested tabs.

Tab Group

High level tabs

Sub Tab Group

Sub tabs from the High level tabs.

So I have built up my page with a placeholder top level tab group, then creating and added child tabs to this, then from this level, I have created a new Tab Group programatically, and programmatically added tabs to this new group.  However, all I am getting is the top level of tabs, with all of the leaf data concatenated under it.  Does ZEN allow nesting of tab groups programatically, or do I have to define them statically on the page?

Thanks
Chris