Steps to reproduce:

1. Create and open a new project
2. Create and open a new UI Document in UI Builder
3. Create a VisualElement in Hierarchy
4. Create a new Stylesheet "Test.uss"
5. Create any class selector in the StyleSheets
6. Drag the class selector onto the VisualElement
7. In the Hamburger menu of the UI Builder's Hierarchy, toggle "Attached StyleSheets"
8. Observe the Hierarchy

Actual results: Nothing happens

Expected results: Locally attached StyleSheet "Test.uss" is displayed next to "VisualElement" 

Reproducible with versions: 2023.1.0a10, 6000.0.73f1, 6000.3.14f1, 6000.4.6f1, 6000.5.0b6, 6000.6.0a4

Tested on (OS): Windows 11 Pro (25H2)

Notes:

• "Type" and "Class List" options display their corresponding attributes properly