Fences divider?

Hello. It would be really useful to have a (horizontal) divider inside fences so we can further categorize icons instead of having multiple fences. This can be really useful in roll-up fences where you can't have too much fences as space is limited if you want to have them placed on screen top/bottom. The divider doesn't have to be anything fancy, just a simple line. Here is a reference picture

Thanks