A Collaborator computer collaborative environment (CCE) instantiated by a computer network includes N Collaborator CCE clients and a Collaborator CCE server. Each of the N Collaborator CCE clients generates message objects each including a nested group identifier and an associated privilege level; the Collaborator CCE server filters the generated message objects and routes only those message objects to an Nth Collaborator CCE client that is a member of the respective group having the group identifier and that has a privilege greater than or equal to the associated privilege level. Corresponding software is also described.