Steps to reproduce:
1. Create a project
2. Create > UI Toolkit > UI Document
3. Double-click newly created UI Document to open UI Builder window
4. Select Project in Library section
5. Hover over UXML Asset and observe
Actual results: Empty field appears next to Library section
Expected results: Field with something in it appears next to Library section
Reproducible with versions: 2021.3.51f1, 2022.3.61f1, 6000.0.47f1, 6000.1.0b15, 6000.2.0a9
Tested on (OS): macOS Sequoia 15.3.1 (Intel)
Note: Issue is also reproducing with Custom Controls Assets