My team currently has a project with a data access object composed like so:

public abstract class DataProvider 
{
     public CustomerRepository CustomerRepo { get; private set; }
     public InvoiceRepository InvoiceRepo { get; private set; }
     public InventoryRepository InventoryRepo { get; private set; }
     // couple more like the above
}

We have non-abstract classes that inherit from DataProvider, and the type of "CustomerRepo" that gets instantiated is controlled by that child class.

public class FloridaDataProvider 
{
     public FloridaDataProvider() 
     {
          CustomerRepo  = new FloridaCustomerRepo(); // derived from base CustomerRepository
          InvoiceRepo = new InvoiceRespository();
          InventoryRepo = new InventoryRepository();
     }
}

Our problem is that some of the methods inside a given repo really would benefit from having access to the other repo's. Like, a method inside InventoryRepository needs to get to Customer data to do some determinations, so I need to pass in a reference to a CustomerRepository object.

Whats the best way for these "sibling" repos to be aware of each other and have the ability to call each other's methods as-needed? Virtually all the other repos would benefit from having the CustomerRepo, for example, because it is where names/phones/etc are selected from, and these data elements need to be added to the various objects that are returned out of the other repos.

I can't just new-up a plain "CustomerRepository" object inside a method within a different repo, because it might not be the base CustomerRepository that actually needs to run.