Hey Sarah,
What you want listed on the Grid is the main customer per record, instead of the customers with all the related contacts. I hope I understood correctly.
You can do this by adjusting the filter for the grid.
Customize the Customers and Contacts List screen (CRM_CustomerList) and Edit the Contacts Grid.
Head over to Step 3 of 9: Filters:
Change the View Name to 'Shared Active Customer Contacts' and make sure that it is the default view:
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Now click on Insert Filter the field will be SpecialType. And the Filter properties should look like:
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Let me know if that works for you.
- Mortaza