Nested namespaces for selective content sharing are provided. In a content management system, content is stored for a plurality of users. The content includes a plurality of content items and a plurality of folders arranged in a plurality of hierarchies. A plurality of root namespaces is established. Each root namespace is rooted to a root folder of an account. A first namespace rooted to a first folder selected from the plurality of folders is established. First permissions are maintained for the first namespace, granting access to a first set of users. A request to share a second folder is received. The second folder is a child of the first folder in a particular hierarchy. A second namespace rooted to the second folder is established. Second permissions are maintained for the second namespace, granting access to a second set of users.