The search fields overlap when the details section in the Details Panel is dragged up as high as possible. This also occurs when when the Details Panel is compressed.
Found in 4.23.1 CL#9631420
1. Open a project.
2. Select an actor in the World Outliner.
3. Drag the details secton as far up as possible.
Results: The search fields are overlapping.
Expected: The search fields don't overlap.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-85258 in the post.