What kind of blueprints can be used as types in other blueprints?

Hi, I just created a blueprint derived from “Object” and I can’t create a variable of this type in other blueprints. This Blueprint (Object) is just a container for some functionalities (Basically a class) used in my HUD graphs. This is why I want the most basic parent class. I don’t need to somehow spawn this object in the world, or otherwise interact with the engine. What class should I derive from ?