UI rectangle progress bar

Hello, please tell me, I searched for a very long time but could not find a solution

How to make a procedural material progress bar as shown here.

there are many videos on youtube how to make a circle progress bar

Tons of ways to do it but generally it is a masked material on top, with a cutout for the “window”, and a scaling mesh or material behind it as the progress bar.

If its a 3d thing it would be 2 meshes. In the UI it would be two rectangles.

Btw Unreal has a built in HUD blueprint ProgressBar:

UProgressBar | Unreal Engine Documentation

here it does without textures

in blender you can procedurally make a material without textures

how to do it in unreal engine?