At this time you can only send two different output screens (plus the main control screen). One is the main output and the other is the foldback screen. They are working on adding the ability to send to a third output like you would send to a Live Stream. They haven't released when that will be released, but if you have the Subscription you will be able to update to that build when it is released.
There are some "unofficial" work arounds that people have been able to get working, but they are more complicated to get working, Unfortunately I'm not well versed in how to set them up, but the instructions are here in the forums.
They will show the same feed. If you setup the one towards the stage as the Folback Monitor in EW it will show a slightly modified version of the FOH (Front Of House) feed. It includes a clock, what the next item will be or the first line of the next slide. It also doesn't show the background that the FOH shows, just the text and/or the picture or video that is playing. For example you aren't able to show a presentation on one and song lyrics on the other though.You can use the CLEAR button the keep the background image or video up on the main FOH screen while displaying the song lyrics, scrpture verses, or other text on the Foldback screen though as the Clear button only clears the text of the FOH display.