Hi
I'd like you to delete saved saves in the cloud
Only from The Witcher 3

Or if there's any way I can do it

Thank you

You can delete them yourself.

Open Witcher 3, once you're on the main menu, alt-tab out, locate the save folder in documents/witcher 3/saves/ you can remove or move them to another location.

Once you've done. Alt-tab back to the game, exit. And gog will sync the saves out of your cloudspace.

1.If you have the game installed you can do what KoalaNalle suggested.
2.If you don't have the game installed you can disable the 'cloud saves' function via the GOG Galaxy settings. It should delete any cloud saves, but for ALL the games that support the 'cloud saves' function.
3.Else, you can do the same, with the game installed or not, by going to your library and disabling the 'cloud saves' function in the game's settings.
I don't really know if steps 2 and 3 actually delete your cloud saves, but at least they won't be downloaded or uploaded, untl you re-enable the 'cloud saves' function.