Today, I was doing some research on how Combined Sections work. I found this video from the University of Southern Mississippi:
PeopleSoft Class Schedule Entry: Combined Section
Watching the video helped me figure out what I needed to do. The version was a little old, but I found the same page at Curriculum Management > Combined Sections > Identify Combined Sections (in version 9.0).
It looks like there are a lot more videos here that might prove helpful in the future, so I am bookmarking this page!
University of Southern Mississippi: PeopleSoft Class Schedule Entry