Make a mask from a blend node with a MAX blend

[Santiago Pereira Carrasco 1]

Hey, I want to make a mask to add color for example in this situation:



I have a material (dirt/ground) and I can change the height with a histogram range node blended with the stones or bricks with a blend node set to max. How should I mask this to add color separately to this 2 parts?
the original tiles mask is not useful because when the dirt gets higher than the bricks it covers it.

[Santiago Pereira Carrasco 1]

I found my own answer, shaing the result here:
You have to create another blend between them, this time you subtract the stones from the mortar, this will give you positive values only where the mortar is higher, then you use a histogram scan with position and contrast to 1 and you get your binary mask