This is currently not possible in the current desktop app.
Later in 2015, you will be able to do this when an update comes out to the app.
Here is a sneak peek:
If you want to try it out now, download the desktop beta app:
The beta app will install over the current app you have. The beta app is missing quite a few features at the moment and the performance isn't yet up to the standards of the current app. The beta will be getting back those features and will have improvements in future udpates.
