Is it possible to have a 3-4 layer material blend?

[frank.meinl]

Hi, is it possible to have a material blend between 3 or 4 different materials. Let's say i want to have stone tileable material blending with rust, dirt and maybe some variation of the stone, each of them having their own setup (diffuse,metal/roughness, normal map) mixing them together with an R+G+B+A mask texture? I did not find the right combination node on how to combine the different PBR shaders for example into one main PBR shader that controls the main unique bake. Because I want to have a unique normal map over everything.

[lee_griggs]

You can chain multiple materials with the mix_material.

[frank.meinl]

But is it possible to blend a PBR material normal map over everything? Lets say I have a "lowpoly" column baked from a highpoly mesh. But instead of using 1 single diffuse texture I want to have material mix of stone, dirt, leaks and rust. (all tileable textures setup as PBR materials) With the linear blending it seems only the normal map of the single material is rendered, not the baked unique normal map from the highpoly. What I´m saying is it possible to have nested shaders under the PBR shaders and have a blend between all normal maps?