Do you mean setting up functions to be called in your main blueprint? You can set a large portion of your blueprints up within functions, and then call those functions into your main event graph. To do this, you can hit the New function button at the top left of the event-graph window. You can create blueprint interfaces for interactions between multiple blueprints (an example of this can be found in the security cameras of the blueprint office content example). Here is some more information on blueprints that you may find helpful: