When you share a folder, the defined Share Access applies to all its content, including the sub-folders and their content.
A sub-folder cannot have a share access level that is more restrictive than the primary folder. For example, if the primary folder is shared with [email protected] with Collaborator access, then [email protected] will have a minimum of Collaborator access to all the sub-folders and the content within. For more information, see Changing User Access Level on Sub-folder.
A sub-folder can have a share access level that is less restrictive than the primary folder. For example, if the primary folder is shared with [email protected] with Guest access, then U[email protected] will have a minimum of Guest access to all the sub-folders and content within. However, [email protected] can be explicitly granted Collaborator access to one or more of the sub-folders and all of the subsequent content.