The group layer needs an option to be expanded at the start. The group layer loads as closed and you can't see the map choices inside until you expand it, which means we need to expect users to know it is a group layer hiding many map options and they need to open it.
As most users are not map interface experts, the only option is to write lengthy text on the group layer name instructing people to open, which is a bad workaround.
See attached for a visual.