The actual problem:
This is on Ubuntu 20.04. I can't start playing Counterstrike GO (CSGO), because as shown in the screenshot below, the green start button is not visible in the viewing area of the screen. I can't even change the settings of CSGO, because after changing the settings, I'm required to click a button to confirm it, and the button is located outside the viewing area. This is a Dell 2030M monitor (20 inch) with a max resolution of 1600x900. I can't even report the problem to the CSGO team because Steam has this silly requirement that I need to spend at least $5 to use the support channel.
What I'd like to do:
In Ubuntu 16.04, if I moved a window partially out of my current workspace, I'd be able to see the other part of the window when I switched to the other workspace. But when I switch to the bottom workspace in Ubuntu 20.04, it does not show me any part of the window that belongs to the top workspace. What can I do to view part of the window that's outside my viewing area (and to be able to click the necessary buttons)? I tried using Gnome tweaks and using "static workspaces". No use.
An alternative would be to have a way to force the entire application window to fit into the current workspace.
You will need to move the window in your viewport to access that button it either 1) you cannot increase the resolution of your screen or 2) reduce the window of the application.
This can be done rather easily when you hold the window action down then drag the window. Your mouse pointer then can be anywhere in the window.
Thus: hold the window action key, Super by default, and drag the window to see the button.
Alternatively, you may consider moving to a desktop environment where workspaces are visually connected.
Some background on how it works on Gnome Shell
In Gnome Shell, workspaces are different visual environments. So it is not that a window moved to the edge will "spill" to another workspace.
The behavior you expect is only there with multiple monitors. Additional monitors are spatial extensions of the first workspace.
By default in Gnome Shell, you can only switch workspaces on the primary monitor, on the second monitor whatever item from the first workspace you placed there (or that spills over from the left screen will remain visible. In recent versions, an option is exposed to have all monitors switch workspaces. So if you change to another workspace, the second monitor will be an extension of that workspace instead of remain on the first.