@Entity
....
public class ReferralRequestEO implements Serializable
{
 ....


 private List<ReferralSpecialtyEO> specialties;

}


@Entity
....
public class ReferralSpecialtyEO implements Serializable
{
  ......
       private WorkflowTransitionEO activeTransition;

}

@Entity
.....
public class WorkflowTransitionEO implements Serializable
{
   ......
   @Temporal(Temporal.TimeStamp)
   private Date transitionDate;
   
   @oneToOne
   joinColumn(...)
   private InstructionEO instruction;
}

@Entity
.....
public class InstructionEO implements Serializable
{
      private String instructionType;
}