Map to Material can be used to assign Map shaders (that are not closures) from the Arnold 'Maps' group in the Slate Editor directly to objects in your scene. It can be found under Material/Map Browser-> Materials-> Utility in the Slate Material Editor.
Connect the input shader (Map) here.
In the example below, the output of a Utility shader has been connected to the Texture input of the Map to Material. The Map to Material shader must be assigned to the object to make the shading connection, otherwise, you will not see any result in the render.
Utility connected to Texture Map parameter of Map to Material
This switch should be disabled when rendering surfaces that are non-opaque, such as glass for example.