Make sure to check this documentation page: https://wiki.unrealengine/Creating_Layered_Materials_(Tutorial) It will explain you how to create a layered material (from your material it seems like you are trying to create a layered mat) 
Make sure to check this documentation page: https://wiki.unrealengine/Creating_Layered_Materials_(Tutorial) It will explain you how to create a layered material (from your material it seems like you are trying to create a layered mat)