Question Get "mesh height" in the Sharder Graph

Hello !
I'm kinda new on the shader graph, and there are some principles that are hard for me to understand.

Actually I want to make a shader that simply fill a mesh from bottom to top according to a certain percentage which i settled as parameter.

But it's not filling proportionnaly, so I'd like to add it with : selected% * height / 100, but I can't figure where to get the "height" or anything that I could use as a height.

Here's the screenshot, I would change the 2nd substract with the method that I described.


Thanks for your help !