How to reproduce:
1. Open user-submitted project (compsel)
2. Open the SampleScene
3. Select test1 GameObject
4. In the Inspector window click on the circle icon of the Tt field to open the Select pop-up window
5. Click on the 'Assets' tab

Expected result: test2 prefab is displayed because it contains TestComponent/Assets tab is hidden/A note states that Assets with TestComponent will not be listed
Actual result: test2 prefab is not displayed, even though it contains TestComponent.cs, no information exists stating that assets containing TestComponent will not be listed

Reproducible with: 2017.4.36f1, 2018.4.15f1, 2019.2.18f1, 2019.3.0f4, 2020.1.0a18

Note:
Although test2 prefab is not listed in the Asset tab, it can still be dragged into the Tt field to assign it