public class TestViewModel : IBindingContext
{
 public IReadOnlyProperty<int> Opacity { get; } = new ReadOnlyProperty<int>(15);
 public IReadOnlyProperty<Color> BackgroundColor { get; } = new ReadOnlyProperty<Color>(Color.red);
}

public class BindableVisualElement : VisualElement, IBindableElement
{
 private PropertyBindingData _opacityPropertyBindingData;
 private PropertyBindingData _backgroundColorPropertyBindingData;
 private IReadOnlyProperty<int> _opacityProperty;
 private IReadOnlyProperty<Color> _backgroundColorProperty;
 
 public string BindingOpacityPath { get; private set; }
 public string BindingBackgroundColorPath { get; private set; }
 public void SetBindingContext(IBindingContext context, IObjectProvider objectProvider)
 {
 _opacityPropertyBindingData ??= BindingOpacityPath.ToPropertyBindingData();
 _backgroundColorPropertyBindingData ??= BindingBackgroundColorPath.ToPropertyBindingData();
 _opacityProperty = objectProvider.RentReadOnlyProperty<int>(context, _opacityPropertyBindingData);
 _opacityProperty.ValueChanged += OnOpacityValueChanged;
 
 _backgroundColorProperty = objectProvider.RentReadOnlyProperty<Color>(context, _backgroundColorPropertyBindingData);
 _backgroundColorProperty.ValueChanged += OnBackgroundColorValueChanged;
 SetOpacity(_opacityProperty.Value);
 SetBackgroundColor(_backgroundColorProperty.Value);
 }
 public void ResetBindingContext(IObjectProvider objectProvider)
 {
 _opacityProperty.ValueChanged -= OnOpacityValueChanged;
 _backgroundColorProperty.ValueChanged -= OnBackgroundColorValueChanged;
 objectProvider.ReturnReadOnlyProperty(_opacityProperty);
 objectProvider.ReturnReadOnlyProperty(_backgroundColorProperty);
 _opacityProperty = null;
 _backgroundColorProperty = null;
 SetOpacity(100);
 SetBackgroundColor(default);
 }
 private void OnOpacityValueChanged(object sender, int newValue)
 {
 SetOpacity(newValue);
 }
 private void OnBackgroundColorValueChanged(object sender, Color newColor)
 {
 SetBackgroundColor(newColor);
 }
 private void SetOpacity(int value)
 {
 style.opacity = value / 100.0f; // You can write a PropertyValueConverter<int, float> for this conversion.
 }
 private void SetBackgroundColor(Color newColor)
 {
 style.backgroundColor = newColor;
 }
 public new class UxmlFactory : UxmlFactory<BindableVisualElement, UxmlTraits> { }
 public new class UxmlTraits : VisualElement.UxmlTraits
 {
 private readonly UxmlStringAttributeDescription _bindingOpacityAttribute = new()
 { name = "binding-opacity-path", defaultValue = "" };
 private readonly UxmlStringAttributeDescription _bindingBackgroundColorAttribute = new()
 { name = "binding-background-color-path", defaultValue = "" };
 public override void Init(VisualElement visualElement, IUxmlAttributes bag, CreationContext context)
 {
 base.Init(visualElement, bag, context);
 var bindableVisualElement = (BindableVisualElement) visualElement;
 bindableVisualElement.BindingOpacityPath =
 _bindingOpacityAttribute.GetValueFromBag(bag, context);
 bindableVisualElement.BindingBackgroundColorPath =
 _bindingBackgroundColorAttribute.GetValueFromBag(bag, context);
 }
 }
}