The present invention is directed to technology for determining the members of groups. A group can have static members, dynamic members and/or nested members. An entity is a nested member of a first group if that entity is a member of a second group and the second group is a member of the first group. There can be multiple levels of nesting. For example, an entity can be a nested member of a first group if that entity is a member of a second group, which is a member of a third group, which is a member of a fourth group, . . . , which is a member of the first group. The present invention can determine the membership of a group, including the static members, dynamic members and/or nested members. Furthermore, the present invention can be used to expand one or more groups so that future requests to view the membership of a group can be performed in a more efficient manner.