Articulate Rise: Creating Series (Categories) like the samples shared (e.g. Next Big Idea Club)

I found a section in Rise that arranges existing templated lessons into Series (also called Categories, I believe). It seems to compile short lessons into series so that users just experience a short micro-lesson, knowing ahead of time its duration.

I can't figure out how to set up my own series and display in the same fashion. What am I missing?