How to make my character walk both behind and in front of an object.

I'm trying to code my character to be able to walk in front of a 2d house and be fully visible but also to where they can walk behind the house and be concealed by the object. How do I make it to where the Z elevation or layer alternated based on how close the y value is to the bottom of the screen?

Like this?

howtoconstructdemos.com/z-sorting-in-an-isometric-view-game

Yes thats perfect thanks