Landscape painting materials

I would like to paint on my landscape. (I am aware of the basic setup on how this works in the material nodes using a layer blend node)

However, I’m not sure how to have materials blending that each has unique values. For example, I want one of my materials to have a particular look using a set up of nodes with emission, multiply, specularity, metallic etc. However, I don’t want that to affect any other materials within this landscape setup. In my case, I have a wet and a dry version of the same texture material. I have the wet material set up with a specific set up of nodes as well as a different material for the dry version, however, I can’t seem to find a way to blend these two together on the landscape. Thanks!