This is a challenge akin to writing something that (might) work for a game story - it's shifting the character arcs onto the supporting characters, the characters who aren't the story focal point (protagonist).

Take three characters (you can use more, but it's harder).  One of these is the protagonist, the one making their own life, telling the story. Give them a goal.

The other two characters may help or hinder (they can do either, but if they're both helping or both hindering, they should do it in different ways). They also each have individual goals. These goals don't particularly mesh with your protagonist's, and they directly contradict each other.

Example: C is your protagonist. She's locked in a building and wants to get out (goal). G currently controls the building, and wants C to stay there to perform a task (goal). W starts out helping C because he (secretly) wants control of the building (goal).

Now, the trick is to create character arcs for G and W. Have them go through dramatic changes emotionally and as a person - think Hero's journey, though it doesn't have to be anything grand. So, create an emotional arc for G and another for W. Now you have to work out how to get there through C's actions. C is still the protagonist. It's just that C's actions are causing emotional arcs in other people. Remember The Hollywood Formula? - well, one of G and W is the hero, one is the antagonist. C (the actual protagonist) is the relationship character.

Now, either W or G has to be the 'hero' - this is the person that C will have a reconciliation with. In our example above, W is only using C to help him achieve his goal of taking over the building. Once he's done this, he betrays C and uses her in the same manner G was earlier. Near the end, however, W realises his mistake and apologises to C - they reconcile. So that makes W the hero, and G the antagonist.

You have your three goals, and your two arcs (your protagonist doesn't get an arc, they may or may not achieve their goal.). The arcs are a direct result of the protagonists actions and interactions with the characters. Now write the story.