I don't believe there is a way right now, but I sent a message out tonight asking about it, and suggesting it for a feature request.
I think the only way now is to use the global search in the main Roku menu.
Basil wrote:Roku, the device, is available in the U.K. and many places across the world. It has apps for BBC, ITV, among many many others. The app "The Roku Channel" is only available in the U.S.