1. First navigate to your config settings and find "Customer Supplied Inventory - Exclude From Allocation". Set the value to 0.
2. With this config turned off, customer supplied material will now be included in allocation and shown on MRP.
3. When displayed on MRP there will be a purple hyperlink calling out that this material is sometimes customer supplied.
4. Follow that hyperlink to the part waterfall, and any orders that this part is customer-supplied on will show in purple. Orders where you purchase the part will be shown in the standard black.