The entity type is displayed as a root from which you accessed the inverse hierarchy in the screen Inverse Hierarchy: Entity Type <entity_type_name>. The next level up is displayed below, that is, the data model(s) directly superior to the entity type. This means that the "higher" an object is in the hierarchy, the "lower" it will be displayed here.
To display the color key, choose Utilities ® Color key....
You can change the display of the inverse hierarchy.
You can also call a general where-used list for modeling objects with Utilities ® Where-used list.