The following procedure is only for $XDG_SESSION_TYPE x11.
Notes:
- It uses xdotool which is in the Universe repository.
- It assumes you've categorized your terminal windows in such a way that each group has a common string in the title (not present in any other open windows).
- In the example below, there are two groups each with three open gnome-terminal windows:
- Earth 1
- Earth 2
- Earth 3 and
- Wind 1
- Wind 2
- Wind 3
Important:
To ensure that the terminal window's title does not change, I had to first comment out the following lines from ~/.bashrc. If this is not done, the title will reflect the current working directory instead of retaining the title you set:
case "$TERM" in
xterm*|rxvt*)
PS1="\[\e]0;${debian_chroot:+($debian_chroot)}\u@\h: \w\a\]$PS1"
;;
*)
;;
esac
I named each window using
echo -en "\033]0;New title\a"
Note that xdotool, as used here, won't handle windows named using
wmctrl -r :ACTIVE: -N "New title"
See the answer to Setting terminal window's title: wmctrl versus xdotool for a thorough explanation.
The following animated gif will illustrate using another "master" terminal, located at the top of the screen in the image, to issue code to minimize or maximize a particular group of windows.
To do so, I added the following functions to my ~/.bashrc:
mmm(){
echo "enter KEYWORD" && read KEYWORD && xdotool search --name --onlyvisible "$KEYWORD" > /tmp/tmp.txt
}
xwn() {
while read p; do xdotool windowminimize "$p"; done </tmp/tmp.txt
}
xwx() {
while read p; do xdotool windowactivate "$p"; done </tmp/tmp.txt
}
mmm
uses xdotool to search for the string "KEYWORD" provided by the user. "earth" in this example, is common to one group of terminal windows to be acted on. xdotool produces their window identifiers which is directed to a temporary file.
xwn
uses xdotool's windowminimize action to minimize the windows specified in the temporary file.
xwx
uses xdotool's windowactivate action to maximize the windows specified in the temporary file.
- Note that, depending on what else has been done, it maybe necessary to run
mmm
immediately before xwn
or xwx
.

I had to use mogrify -type Grayscale -depth 7 *.png
to scale down the size of the gif.
Super
+M
to mimic MS Windows usage. (Go to Settings | Devices | Keyboard | Navigation to set it.) – FedKad Jul 22 '19 at 16:26