How to figure out the black/white value of a shader?

Is there a way to figure out the black and white color of a map that is added to the base texture in a surface shader.

I would like to know how to calculate o.Albedo - o.Emission to have only the ambient b/w color of the shader, except that it seems they are both read only values?

Same goes for normals, i would like to know o.Normal b/w value that is added to the ambient b/w color.

i want to make kindof metal and other effects, because every angle corresponds to a b/w value, perhaps by changing the simple black linear gradient to a perlin noise of different colors will make some reflection effects?