You could handle this by having two Teams: One for internal work, one for Marketing Requests. (Both Teams can have exactly the same set of members.) Then it will be clear that internal projects live in the Internal Work team etc.
Also see Streamline your organization: Effectively organize teams, portfolios, projects, and tasks within Asana
and
https://help.asana.com/hc/en-us/articles/14211286206875-Team-basics
It will help if you stop thinking about folders, as that mental model won’t get you too far, and just think about the structures available in Asana, and your overall goals.