You can use git switch - to switch to the previous branch. In the following example, we see switching back and forth between branches main and my_dev_branch:
C:\git\my-repo [my_dev_branch]> git switch -
Switched to branch 'main'
Your branch is up to date with 'origin/main'.
C:\git\my-repo [main ≡]> git switch -
Switched to branch 'my_dev_branch'
C:\git\my-repo [my_dev_branch]>
Edit: Old habits die hard. Updated to use switch instead of checkout since switch has a clearer responsibility. Obviously they work exactly the same for this scenario.
There's more! Well, it's more a bash thing than a cd thing.. in bash the variable $_ refers to the last argument to the previous command. So you can do the following:
> mkdir -p my/nested/dir
> cd $_
> pwd
/home/user/my/nested/dir
It's handy for a whole host of things, like piping/touching then opening a file, chown then chmod, etc.
On many terminal emulators you can also use Alt-. to search through your history of previous arguments, so mkdir foo followed by cd [Alt-.] will populate your command line with cd foo for example. If you have some other command in between you can just hit Alt-. repeatedly