As far as I can tell Unreal does not support this natively, but it would be platform specific.
On windows you should be able to use the info here:
https://www.microsoft.com/msj/0697/monitor/monitor.aspx
Essentially what you do is you enumerate all your monitors, find the one you want, and then move your application to there and maximize it.
edit:
Looking in WindowsWindow.cpp, you probably want to write a function very similar to GetFullScreenInfo that just enumerates the windows instead of using a rectangle and then gets the corresponding data from it, then use MoveWindowTo to move the window to there and MAximize to biggify it.