How do Box folder permissions work?
Permission levels on Box follow a ‘waterfall’ design in which individuals only have access to the folder they are invited into and any subfolders beneath it. Please note that users can be invited into folders but not individual files.
For example, if John was invited to be a collaborator on the Internal Collaboration parent folder, he would see this folder and all subfolders (i.e., Design, Finance, Legal, etc.).
However, if John was invited to be a collaborator in the Marketing subfolder only, he would only see the Marketing, Approved Collateral, and In-Progress Collateral folders. He would never see the Design, Finance, and Legal folders.
If an individual is a collaborator on a parent folder, their access level for a subfolder cannot be changed. For example, if John was invited into the Internal Collaboration folder as an Editor, you could not change his access to Viewer in the Marketing folder. See What Are the Different Access Levels for Collaborators? for additional details.
If you’d like to send a document to an someone who is not a collaborator in the folder, use a shared link! The recipient of the shared link will be able to preview or download the document.