How to reproduce:
1. Open the attached project
2. Go to the Project window and open Test prefab in the Prefab mode
3. In the Hierarchy window select Test child Cube, drag and drop it in the Inspector window/Issue Test/Element 0/T
4. In the Hierarchy window select Test child Empty, drag and drop it in the Inspector window/Issue Test/Element 1/T
5. Exit the Prefab mode
6. Drag the Test prefab from the Project window to the Hierarchy window
7. Go to the Inspector window/Issue Test/Element 1/T select Empty and see the highlighted reference

Expected: Selecting public Transform object "Empty" highlights reference in the Hierarchy window
Actual: Selecting public Transform object "Empty" highlights Assets folder in the Project window

Reproducible with: 2018.3.0b6, 2018.3.0b9
Not Reproducible with: 2018.3.0a6, 2018.3.0b5, 2018.3.0b10

Note: Couldn't test on the earlier versions because the feature was introduced in 2018.3.0a6
Fixed in: 2018.3.0b10