You can save the value returned by calls to new NavSection, then call show/hide on any sections you wish after the call to “menu.generate()”.

Example:

  var menu = new NavBar(...);
  var sec1 = new NavSection(menu, ...);
  var sec2 = new NavSection(menu, ...);
  var sec3 = new NavSection(menu, ...);
  menu.generate();
  sec1.hide(true);
  sec2.show(true);
  sec3.show(true);

(we pass "true" to show/hide calls in order to force it to be un-animated).

I know the procedure is a bit awkward, but this is it for now..  In the next version we plan to provide a completely differet, much more easier to use API (but the bad news is that it'll not be backwards compatible).