I think Rich removed it when he fixed the wrap around problem that some of us complained about. It was never my intention to have him remove that tab, just shorten up that title to conserve characters. He did combine the digital libraries under one tab.
Actually, all you have to do is go to the top of the page, and just below the advertising, and you'll see all the levels of your current location. Then you can select the level of the tree that you want to go to.
