How to create Enum inside Material editor? (Like the Unity ones HLSL)

Hi there,

First time using Material Editor, im used to write my shaders in unity.
Mostly of my shader have Enum so the designer can easy change some shader property with a drop box.

Im trying to make an enum inside Unreal Material Editor for values: 0 , 1, 2 but i cant find any reference.
(i learp them in lerp(c,lerp(a,b,T), T))

Idea is like this: