To me what you suggest there is more a breadcrumbs bar than a
navigationbar…
I'm all in favor for the introduction of a breadcrumb or a side menu
like the original plone one, maybe starting from the 3rd level only. As
I repeatedly stated, I'm concerned there might be navigational issues
if we just rely on the tab-bar and the secondary navbar.
Ah, what i mean is have the categories on the right hand side of the
page as menu. When user clicks "about" the right hand menu would show
links relating to the about tab for example.