It seems Jermfire and I understood your question differently. He understood it as how to make a health bar that stays pinned to the player. I understand your question to be, how to make a health bar that handles multiple player levels so no matter how high the players health is, it still shows the correct length. I have attached an example if that is really what you are looking for. Take a look at it. Basically you set the length of the health bar to 100 * (CurrentHealth / MaxHealth).
I hope you get what you need and good luck with your project.
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