Catalog groups are a feature of Oracle BI EE that allows administrators to organize users and application roles for security administration purposes.
In Oracle BI 11g releases, catalog groups primarily allowed for backward compatibility with earlier releases. In 11g releases, you were encouraged to migrate to and use the more powerful application roles feature for organizing and managing users.
In Oracle BI Release 12c (12.2.1.1), catalog groups are deprecated. The catalog groups are migrated by the upgrade process to Application roles.