Backup and restore

Hello,
Sorry, if this issue has already been addressed. Our district is interested in having teachers easily share resources and activities that they have created in Moodle. We have several ideas on how to do this, but what keeps being a sticking point with each plan is the course files. When you backup or share activities, you can either include the course files or not, but you can't include only a particular set of files. Is there a fix that allows you to include only the particular files associated with an activity?

The problem that we are running into is when a teacher A shares an activity with teacher B (teacher B gets all of teacher A's course files if the activity required a file) and then teacher B shares an activity with teacher A (sending all of the course file back). Sometimes this has caused strange errors. Also this clutters up the course files of teachers as more and more people share activities with each other.

Thank you!