Heya,
I just looked into filtering assets (e.g. by their path) in an object picker from an ObjectField in UIToolkit. This would be similar to EditorGUIUtility.ShowObjectPicker, but for UI-Toolkit.
What I would wish for is something along the lines of objectField.filter = "h: path:/Collectables". Is there already something like this available or possible to do with a workaround?