Setting multiple key bindings for the same action in GNOME
In GNOME, you can only set one key binding for a given action using the Settings app (under Devices → Keyboard) even though the settings data structure itself accepts an array.
You can, however, set multiple key bindings per action by installing the dconf Editor app or through the command-line using the
To install dconf Editor:
sudo apt install dconf-editor
To change key bindings via the command-line (e.g. for switching the windows of an application):
gsettings set org.gnome.desktop.wm.keybindings switch-group "['<Alt>Above_Tab', '<Super>Above_Tab']" gsettings set org.gnome.desktop.wm.keybindings switch-group-backward "['<Shift><Alt>Above_Tab', '<Shift><Super>Above_Tab']"