@Entity
public class ComplaintModel {
//code
    @Embedded
    private ComplaintOrder complaintOrder;
}

@Embeddable
public class ComplaintOrder {
   @OneToMany(cascade = CascadeType.ALL, mappedBy = "complaint")
   @JoinColumn(name = "COMPLAINT_ID", referencedColumnName = "COMPLAINT_ID")
   @Cascade( { org.hibernate.annotations.CascadeType.MERGE,
         org.hibernate.annotations.CascadeType.SAVE_UPDATE,
         org.hibernate.annotations.CascadeType.DELETE_ORPHAN })
   private Set<CompliantLot> compliantLots = new HashSet<CompliantLot>();
}

@Entity
public class CompliantLot extends BaseEntity {

    @ManyToOne(cascade = {CascadeType.PERSIST, CascadeType.MERGE, CascadeType.REFRESH})
    @JoinColumn(name = "COMPLAINT_ID", referencedColumnName = "COMPLAINT_ID", nullable = false)
    private ComplaintModel complaint;
}