Are you asking about creating lists within your list?
You can also browse people's plant lists here:
https://garden.org/lists/
The ones that fascinate me are those with just a handful of plants, usually want lists. I'm always curious about other people's wish lists. They are usually the kinds of plants one will never see at the average store that sells plants. I still have a list of those from my earlier garden days, before I realized they are plants I'll never see. Hey, I'm babbling... LOL!