This question is about the new Google Drive for Desktop on a MacBook Pro with Catalina 10.15.7.
When you install the "new" Google Drive for Desktop on Windows you get an option in the preferences dialog to turn off streaming and just continue to use mirroring -- you can specify which folders to sync.
I was just forced to install the new Drive on a MacBook in place of Backup and Sync, and there does not seem to be any such option. It wants to sync my entire hard disk to Google so it can stream the files, which I do not want to do.
The Preferences dialog for Google Drive on the Mac looks completely different from the one on Windows and lists no options to control anything except Launch on Startup and some cache directory settings.
In Finder I now see TWO "Google Drive" folders. One is my old Google Drive folder and a new one, containing the same files, but all having "cloud" badges indicating they're being streamed.
How do I make Drive for Desktop confine itself to only mirroring, the way I have it set up in Windows?
[It doesn't help that Google overloaded the terms "drive", "stream" and "mirror". Web searches turn up lots of hits for the old "Google Drive" and the old "Google Drive File Stream" but almost nothing for the new integrated version]
EDIT: Here's what I see in Finder and on my desktop
Finder showing two Google Drive folders
After clicking on the Google Drive taskbar icon
After clicking on the account
After clicking on the Gear icon
The same dialog is seen when clicking the gear in either the Activity or Account view.
None of this looks at all like the screenshots shared by @JanacMeena