OneDrive enables your users to work on documents and share those documents with different people inside your company and with external users. In case of sharing customers often asking if the author gets a notification if someone shares his / her documents a second time. There are two places where the configuration for those use cases can be done.
OneDrive Admin Center
In the admin center you can do some setting like this:
So the Owner gets an E-Mail if other people are invited, external users accept inviations or an anonymous link is created.