We have the scenario where the same Contact supports multiple Customer sites for their company.
Our current setup is that we create that Contact against each Customer, so there can be 30 instances of the same Contact, each with a different Customer selected.
How can we have a single Contact for a single actual person/email address and use them across multiple Customers?
We filter the available Contact selection to only Contacts that are linked to the selected Customer (Account) in a Case.