Mistakenly moved desktop files and folders to cloud

There is no separate option for Desktop; you would need to turn off Desktop & Documents which affects both Desktop & the Documents folder. See the following from Add your Desktop and Documents files to iCloud Drive - Apple Support

Turn off Desktop and Documents

1. From your Mac, choose Apple menu  > System Preferences. Click Apple ID, then click iCloud. On macOS Mojave or earlier, choose Apple menu  > System Preferences, then click iCloud.
2. Next to iCloud Drive, click Options.
3. Deselect Desktop & Documents Folders.
4. Click Done.

What happens when you turn off Desktop and Documents

When you turn off Desktop & Documents Folders, your files stay in iCloud Drive and a new Desktop and Documents folder is created on your Mac in the home folder. You can move files from iCloud Drive to your Mac as you need them, or select all of your files and drag them to the place you want to keep them.

If you uncheck the box of desktops and documents .

It will prompt the items from this desktop and the documents folder are available in iCloud Drive , to remove items from iCloud Drive , move them to your desktop and documents folder on this Mac , click on show in finder .

Again open system preferences > iCloud > iCloud Drive > the box of desktops and documents box is unchecked , tap with cursor over the box , a circle rotates setting up the box gets checked .

You will notice a folder is created literally on the desktop , tap it a pop up window appears the items on this desktop on this Mac have been moved into a new folder called “ Desktops - Apples Mac book …( the name of Mac will be written in the existing desktop folder in iCloud Drive , you can combine the contents of these folders any time , click on show in finder .

If you right click on the folder created on the Mac and move to trash , restart the Mac and empty the trash , but again the documents are placed in a right place in iCloud Drive as well in iCloud server .