Library Administration: Prevent external sharing at library level

Could we introduce a control to allow Library Administrators to specify that no user can share with an External address?

The scenario is that we have a lot of users working with sensitive content, all have Edit permissions but we don't want them to be able to share to their personal addresses or to other companies.

Ideally a control to prevent any share outside the domain, but we could also work with a check to only allow sharing to an address within a specific Google Group, if that's easier to implement.

We need this at a library level, because in many libraries External sharing is permitted (or encouraged) so we don't want to turn it off for the domain, but for sensitive libraries only we want to prevent this.