Left Toolbar > Project Nodes > Material Switch
The Material Switch node takes as input multiple materials and returns as output the material defined by the index attribute.
On the left toolbar choose Project Nodes > Material Switch
Drag the Material Switch icon into the Node Graph.
Connect the input: material.
material
The material value that will be received by the custom node's node graph as input. Material Switch nodes that have connected outputs are used by the Node Graph node as inputs in the custom node.
material
The material value that will be returned by the custom node's node graph as output Material Switch nodes that have no connected outputs are used by the Node Graph node as outputs in the custom node.
Index
material that will be returned as output.