Custom branching gradeing with SCORM 1.2

You can designate multiple quizzes as final assessments, and include each of those Results slides in the Tracking Options. 

Note that Storyline will base completion on and submit data from the first quiz that the user completes.

Another option: steer all users to a single Result slide. Select "Only score viewed question" in the Quiz Settings. Note, though, that this would score questions from multiple branches as one quiz.

For future reference, this Exchange Best Practices section is for general questions about eLearning. You’re asking how to do something in the software. That type of question is a better fit in the Discuss Articulate Products section of the website. That's where those of us who regularly answer questions about how to use the software spend more of our time. And that's where more folks go to search for answers specifically related to Storyline, Rise, and other parts of Articulate 360.