You can add complex objects to represent more than one class definition, such as documents represented as business objects. For example, document is a collection of different objects such as master, revision and version.
Click Add Business Object to add a new row.
Select the master class definition from the list in the Name column.
You cannot select SPFDesignFile as a business object from the class definition list because it terminates the relationship between the file and respective document during the content discovery task.
Type the Keyword and Display Name.