When you create a scenario with the Studio, it's automatically attached to your active group. Your learners find it in their library, alongside the scenarios already available.
A scenario belongs to your group
A scenario you compose is specific to your group: only that group's members can see it. Another group's scenarios are never visible to you, and vice versa.
Adjusting how it's displayed
From your group's scenarios page, you can tweak a scenario's presentation without touching its core: its name, its description, its tags, its image. The difficulty level can be filled in once if it wasn't set yet; once defined, it's shown read-only.
A shared resource (a counterpart or a setting from the common library, or from another group) appears read-only. If you edit a resource you own that is used by several scenarios, the change applies to all of them: a confirmation reminds you.