On all my previous Ubuntu machines, I have had a small widget (2X2 grid) in the dock which enables me to switch to one of four workspaces. I have just purchased a new Ubuntu machine and am trying to achieve the same effect. I do not want to use the method which involves going via Activities to the list on the right-hand side of the screen.
I recently upgraded an older Ubuntu machine to 18.4 and the workspace switcher continued to operate correctly there. The switcher is obviously compatible with Ubuntu 18.4 so how can I install it on my new machine?