A view relation, as an arc in the data set diagram, can have direction opposite to the direction of the table relation on which it is based. For example, having a one-to-many relation Customers - Orders, we can create a many-to-one view relation Orders - Customers, based on Customers - Orders, but in inverse order (direction). So, if the Relation object Customers - Orders has Parent = Customers, Child = Orders, the view relation, if inverted, will have Parent = Orders, Child = Customers.

Reference

ViewRelation Class
ViewRelation Members
View Relations