Syncing specific folders to iCloud

The options are to sync nothing, sync the iCloud Drive folder, or sync the iCloud Drive folder and Desktop and Documents. If you only want to sync selected folders you can turn on iCloud Drive (and not turn on Desktop and Documents) and put the folders that you want to sync into the iCloud Drive folder. You can make the iCloud Drive folder easier to access by using Finder Preferences to show it in the Finder Sidebar.

Another method would be to turn on iCloud Drive and also turn on Desktop and Documents and then put any folders that you do not want to sync in a folder or folders in your Home folder (but not in the Documents folder).

I suspect that isn't the answer you want to hear (as it seemed to be already said in the thread you linked to, although I did not read the entire thread), but there aren't other options that you can select as may be available in other cloud services. If so, you may want to provide feedback to Apple via Feedback - iCloud - Apple

See this article iCloud: Use iCloud Drive on iCloud.com

Organize files in folders

You can organize files and folders in iCloud Drive. Your changes appear on all your devices set up to use iCloud Drive.

• Create a folder: Click the New Folder button in the iCloud Drive toolbar. To add a folder inside an existing folder, double-click the existing folder before clicking the New Folder button .
• Put an item in a folder: Drag it to the folder icon.You can also select several items, then drag one of the items to the folder icon. All selected items move to the folder.
• Put an item in an enclosing folder: Drag it to the small folder icon at the bottom of the iCloud Drive window. If you don’t see small icons at the bottom of the window, make the window taller.You can also select several items, then drag one of the items to the small folder icon at the bottom of the iCloud Drive window. All selected items move to the folder.

Sign with Apple ID and password on www.icloud.com and also open finder , drag and drop folder from finder created ( like in Microsoft ) over the untitled folder 1 created in iCloud Drive ( click on get info to get the details ) .

See these screen shots .

I want to add some more details by reading the old thread question .

See this article Organize your files in Google Drive - Computer - Google Drive Help

See these screen shots and follow them .

Now , enter into iCloud .com by entering the Apple ID and passwords , the details are shared .