Is there a way to change this horizontal box object reference to the desired object reference in the SS?

This won’t work. Have you tried connecting HUD Reference as target? Should do the trick here.

Do you want to play an animation that moves a part of your widget? You could always make a custom event inside the widget and call it since you have the widget reference.

Edit: This is how I do it.

278894-characterblueprint.png

To prevent animation overlap and animation spamming you can add something like this: