Risk roll up at entity hierarchy level

The entity class is set up as Company -->Business Unit-->Division-->Department.

All the entities of the 'Department' entity class are downstream of entities of the 'Division' entity class, etc.

How does the risk roll up from the entity of 'Department' to the entity of the 'Division entity class up to the entity of the 'Company' entity class?

Out of the box, if we set upstream and downstream entities, we have a rollup of risk only to the entity level. In this example, at the 'Department' entity level, the rollup is of all risks associated with the 'Application' entity.