How to reproduce:
1. Open a new Unity project
2. Open the "Window -> UI Toolkit -> UI Builder" window from the menu
3. Drag the "Progress Bar" Component from the Library to the Viewport
4. Inspect the fields under "Attributes" in the UI Builder Inspector
Expected result: Field for current value exists
Actual result: No field for current value exists
Reproduced on: MacOS 12.3 (Intel)
Reproducible with: 2021.3.3f1, 2022.1.1f1, 2022.2.0a14
Couldn't test with: 2019.4.39f1, 2020.3.34f1 (ProgressBar isn't featured)