How can I add PlayOnLinux programs in the Unity dash?

When you install applications with PlayOnLinux, there is an option to add the a launcher (Desktop file) to the menu. This will create application launcher in ~/.local/share/applications, which means that the launcher will show up in the Unity Dash.

If this does not work, you can choose the option to place a launcher on the Desktop, and then manually move it to this folder.

Now, keep in mind that Unity does not always pick up when a launcher is added to this folder, so in order for the launcher to show up, you must either log out and log back in, or restart Unity.

To restart Unity, run unity in the run dialogue (press alt+f2 to get the run dialogue).