Hi LisaGR123,
Both non-private and private files can be part of a broad channel in Microsoft Teams. You can set up a standard channel where all team members can access and share documents from non-private folders. You can make a secret channel inside the same team that is only visible to particular team members that you invite for private folders. For conversations and file exchange that shouldn't be visible to the entire team, use private channels. In the same team but in separate channels, you can have both non-private and private folders in this way.
Source: https://support.microsoft.com/en-us/office/stan...
Is there anything else you would like to know?
Kind regards,
Jayzar