[Retal]

It's basically the same as in navbar

Navbar dropdown menu looks like this

<li class="popupmenu"><a class="popupctrl">Dropdown title</a>
	<ul class="popupbody popuphover">
		<li>Dropdown item 1</li>
	</ul>
</li>

while a dropdown menu in the navtab looks like this

<li class="popupmenu"><a class="popupctrl navtab">Dropdown title</a>
	<ul class="popupbody popuphover">
		<li>Dropdown item 1</li>
	</ul>
</li>

+ a bit of styling