Hello,
When you browse the repository with Share you can access:
company home > Sites > [YourSite] > dataLists > [YouList]
Choose "+ More…" > "Manage Rules"
There you can create a rule with some conditions triggering some actions.
In your case I don't think the default "send email" action will enable you to complete your task since the person receiving the email have to be chosen dynamically.
So you might want to write your custom script for that. Or maybe someone in the community already developed one.
Good luck,