At this time you can only showcase work that is in your individual Webflow dashboards. Not on Team Plans.
I pay for a Team Plan, although I am the only one currently on it. It's disappointing not being able to showcase my projects without transferring all of them to an individual plan.
That would be an awesome feature to have in Team Dashboards to make those accounts public and showcase their projects. I figure this way teams working together can feature their work in one place.
You can now showcase your team's projects. Create a public profile for your team first and then showcase as many projects as you would like.
Find out more here: https://webflow.com/feature/showcase-sites-from-your-team-account