As noticed on MDL-77227 Overrides page has no easy navigation, as it is in the bottom of the page only.

Steps to reproduce:

1. Create an activity and add a description, activity completion conditions and open or close dates.
2. In the activity navigation under More, go to Permissions.
3. Choose a role e.g. student to override.

Some improvements have been already proposed by the UX team: Figma designs