I think this is impossible but is there any way to hide Files in Notes & Attachments relatedlist of classic view? We moved only Admins to Lightning and wanted to roll out to other users slowly. Now after converting Attachments to Files, in classic view, we can see both Attachments and Files which gives duplicate viewing for users. Our Business team wants to hide Files without deleting them. Is there a way?
I suggest, instead of trying what you are saying, there are 3 related lists related to notes and attachments.
- Notes and attachments
Notes and attachments related list contains both files and attachment but files related list will only contain files, not the attachments.
So, remove the Notes and Attachments related list from your page layout and add a separate related list for both i.e. Notes, files
This way you will remove the duplicate problem. Also, it will ensure that you don't have to rework on converting attachments which users will create after the first conversion you have done.