Aportación realizada por Howard Miller

Imagen de Core developers Imagen de Documentation writers Imagen de Particularly helpful Moodlers Imagen de Peer reviewers Imagen de Plugin developers
I don't think you can. There's no concept of restricting parts of the Gradebook by groups (or anything else).

Having said that, check the 'Course grade settings' in the Gradebook for anything that might help. I'm thinking of the "contains hidden grades" one but I don't really think it's going to help.
Imagen de Core developers Imagen de Documentation writers Imagen de Particularly helpful Moodlers Imagen de Peer reviewers Imagen de Plugin developers
You would just do a SUM on the filesize field in the mdl_files table. Each record contains the userid of whoever uploaded the file. So, yes, if ten people uploaded the same file it would get counted ten times even though it only took up one lot of space on disk. However, is somebody actually going to write this, anyway? I think the OP is looking for an "easy" solution and I really don't think it exists.