Material Input node
Ghost Matter is an addon for Materials mixing ....
Input Material UI
Create custom input socket
Alert
Input names must be imperatively different
Edit Input Material
By clicking on the "pen" icon the node editor switches to Shader Node Editor with the active input material encapsulated in an already open shader group.
Note
Using the Input Group Nodes and Output Group Nodes, it is possible to manage the inputs and outputs of the Input Material node
Create custom output socket from the material
Alert
Output names must be imperatively different