Quickly Combine Multiple Finder Windows With the Option to Combine All Windows
When you have many Finder windows open, managing becomes a chore. How-To Geek notes that there is an option that reorganizes all of these windows into a single tabbed window for easier management.
In Finder, just click Window> Merge All Windows. This will combine all of your Finder windows into one, even if they are in different spaces. This is an easy and quick way to get rid of your desktop clutter.
How to Merge Multiple Finder Windows on macOS | How-To Geek