How can I create custom InputData node for material editor?

I’m struglling about this quite a while, becuase Epic’s documentation about their renderer module is really not helping.

What I’m trying to acheive is add a my own input data to material editor, such as:


I can’t find how to define input data.

More specifically, I need to make custom vertex shader and provide output data as InputData node.

If you know any reference or have ideas, please shared with me.