Making target layers for already edited material

I’ve got massive issue with my project. I’ll try to describe it best as i can

So I’ve already created a low poly landscape material which looks like picture 2 , ingame picture 1.

All I want is to be able to have target layers so i can paint some green parts of terrain in some rock textures , create a texture path etc… Every tutorial i 've checked usually starts with new fresh material and then wires goes to layerblend etc. i have no idea how to connect those wires in this material which i already created so i can have few target layers for the one which is here already, and other textures which i would like to use. PLEASE HELP … :smiley:

Kind Regards