How do I remove files on iCloud Drive but keep them on my MacBook?

Because I use a different cloud backup service, I do not need to backup my documents on iCloud (I want to use iCloud only for backing up and syncing photos, from iPhone to MacBook). It seems that whenever I try to disable iCloud for documents in my MacBook's settings, I will delete the files from BOTH iCloud and MacBook. But I don't want to do that! How do I tell iCloud to simply stop syncing my documents, but not my photos? Thanks in advance for your help!