In a star schema design, how you can filter one dimension by another dimension. How you can find all the products that this customer purchased or all customers who have purchased this product using two separate slicers.
To learn more about star schema:
https://radacad.com/power-bi-basics-of-modeling-star-schema-and-how-to-build-it
To learn more about the direction of the relationship:
https://radacad.com/what-is-the-direction-of-relationship-in-power-bi