Choose which colleagues have access to the folder and what they can do.
You learn to: share a folder with selected colleagues, and give the right role.
Open the top-level folder, click the folder name at the top and choose Share. Subfolders inherit the access. It works with a private folder too: when you share it, it moves from Private to your team.
Turn off Give everyone in the workspace full access and choose colleagues.
Edit suits most people, Read if they only need to read. Click Invite and then Save.