The Nextcloud Teams group sharing function was formerly called Circles
You can find more background information about Nextcloud teams here
You can create a team as any Nextcloud user. The user who creates the team will be the Team Owner within Nextcloud and will have administrative permission to configure the team, add and remove members and delete the team at any time.
Before setting up your team please see our recomendation for creating a special Nextcloud user for sharing files with a team.
Review our recommended Nextcloud team configuration options to ensure the best accesibility and privacy of your team.
You can now share files, folder and calendars with the name of the team just like you would share with any other user. See these related guides: