Delete shared folders in Notes on iCloud.com
In Notes on iCloud.com, move the pointer to the right of the folder you want to delete in the sidebar.
Click , then click Delete Folder.
One of the following happens:
If you are the owner: the folder is removed from the devices of everyone you shared it with. You can recover your recently deleted notes from your Recently Deleted folder.
Notes in the folder you delete are moved to the Recently Deleted folder, where they remain for 30 days. During this time you can still view and recover them. After 30 days, notes are permanently removed. See Delete and recover notes on iCloud.com.
If you are a participant: The folder is removed for you, but the owner and other participants can still access the shared folder and all of its content. The folder does not move to your Recently Deleted folder. You can open and edit the folder again by clicking the original link that the owner shared, unless the owner stopped sharing the folder.