is there a way to view two separate documents side by side?

In Office products, it’s under view i think, and is called “Arrange all”, and will place all open documents side by side or one above the other. Can this be done in Libre Office?

In Libre open the two documents you wanted to view. In each one go to ‘view’ tab and then to ‘zoom’ at the bottom of the menu. For each document decrease the zoom to about 45% then move each one until you can see both on your screen. The amount you decrease will depend on how large your screen is. Mine is 13" and 48% decrease is just fine. You can always adjust it also. Hope this answers your question.

A simple way is: save one of the two documents as pdf and then open that pdf, next to the libreoffice document

A simple way is: save one of the two documents as pdf and then open that pdf, next to the libreoffice document

Please take a look to this thread:

In Libre open the two documents you wanted to view. In each one go to ‘view’ tab and then to ‘zoom’ at the bottom of the menu. For each document decrease the zoom to about 45% then move each one until you can see both on your screen. The amount you decrease will depend on how large your screen is. Mine is 13" and 48% decrease is just fine. You can always adjust it also. Hope this answers your question.

After you resize the two windows, you can select ‘fit to width’ to maximize the now-reduced viewing area. Also you can customize the main toolbar to show a ‘zoom’ icon at a convenient location for this purpose. If you close the application with the resized windows, they should reopen at the same size next time, in theory at least.