The High Level Architecture allows simulation components of various types to be joined together into a federation to create a common virtual environment. However, with the increased complexity of simulations, not all user requirements can be satisfied by a flat federation. The requirement of selective information hiding naturally suggests a Hierarchical Federations Architecture (HFA) where federations are organized into hierarchies so that a federation appears as a federate in an upper level federation. In order to provide reusability and interoperability at the federation level, a federation should be able to participate in different super-federations without requiring code modification. In this paper, we present an approach to automatically construct the HFA. We describe the information that must be provided by the participating user federations and how this is used to construct the Universal Object Model (UOM) used by the super-FOMs (the FOMs of super-federations). We show how the structure for selective information hiding is generated from the user information and how gateway federates are automatically constructed to support super-FOM independence.