Dragable double progress bar

Hello

What I want to do is a double progress bar that you can drag. The progress bar has a dynamic maximum. English is not my native language so instead of writing a big text, i made an image

The lines with the double arrow must be movable and each box increases the maximum by 10 points (the maximum is the yellow part).

I don’t know how to do that but it would be really cool if someone gave me the answer, every answer can be really helpful. Thank you