One of the easiest ways to identify the four Domains in your story (Objective Story, Subjective Story, Main Character, and Obstacle Character) is by looking at the characters that appear in each Domain. Who are they? What are they doing? What are their relationships to one another? Clearly identifying the characters in each throughline will make selecting the thematic Domains, Concerns, Ranges, and Problems for the throughlines much easier.
From the Dramatica Theory Book