With compiz plugin Wallpaper on ubuntu 16.04, the wallpaper spans across dual monitors automatically. How to disable this? I would like to simply duplicate the wallpaper on both screen.
18.04 and later
Install Tweaks with
sudo apt install gnome-tweak-tooland open Tweaks.
Click the ▾ arrow to show the dropdown menu as marked by the mouse cursor in the below screenshot. Change the span option to Zoom.