1. A system comprising: a database system implemented using a server system comprising one or more hardware processors, the database system configurable to cause: identifying, using the database system, a user identity (ID) received from a computing device as one of a plurality of first user identities (IDs) of first users belonging to a first community maintained on behalf of a first organization by a social networking system associated with the database system, the first users being internal to the first organization, each first user having any one of a plurality of first roles, the first roles comprising an employee of the first organization; providing, to the computing device, access to the first community responsive to identifying the user ID as one of the first user IDs, the access to the first community defined at least in part by a first set of privileges for the computing device to access first social network data available to the first users and to initiate first social networking actions available to the first users, the first social network data comprising at least a first feed, a plurality of first feed items of the first feed, and a first file, the first social networking actions comprising at least communication through the first feed; processing, using the database system, a request to access a second community maintained on behalf of a second organization by the social networking system, the request received from the computing device; identifying, using the database system, the user ID as one of a plurality of second user IDs of second users belonging to the second community, the second users comprising: an internal subset of second users who are internal to the second organization and external to the first organization, each second user in the internal subset having any one of a plurality of second roles, the second roles comprising a customer of the first organization and a partner of the first organization, and an external subset of second users who are external to the second organization, the external subset of second users comprising at least a portion of the first users; and providing, to the computing device, access to the second community responsive to identifying the user ID as one of the second user IDs, the access to the second community defined at least in part by a second set of privileges for the computing device to access second social network data available to the second users and to initiate second social networking actions available to the second users, the second set of privileges being customizable for each second user in the internal subset according to one or more attributes comprising at least a second role of the second user, the customizable second set of privileges for a second user being restricted with respect to the first set of privileges to limit: access by the second user to the first feed, one or more of the first feed items, and the first file, and initiation by the second user of communication through the first feed with one or more of the first users not belonging to the second community, subscription to a user-selectable one of a plurality of work records stored in a database of the database system, and interaction with the first file.