Spring Data JPA ONLY FOR PROFESSIONALS

Question

My goal is to create multiple entities (Subbox) from a single entity (Box), just like Matryoshka dolls. To abstract what we are addressing here, consider the following scenario:

First we have an entity "Box":

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Entity
@ToString
@Table(name="box")
public class Box {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "idbox", updatable = false, nullable = false)
    private int idbox;

    @Column(name = "brand")
    private String brand;

    @Column(name = "size")
    private BigDecimal size;

    @OneToMany
    private Set<Subbox> subbox;

    @OneToMany
    private Set<Content> content;
}

and another entity Subbox:

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
@Entity
@ToString
@Table(name="subbox")
public class Subbox {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "idsubbox", updatable = false, nullable = false)
    private int idsubbox;

    @Column(name = "brand")
    private String brand;

    @Column(name = "size")
    private BigDecimal size;

    @ManyToOne
    @JoinColumn
    private Box box;

    @OneToMany
    private Set<Content> content;
}

If we query from Subbox, we should get something similar to that:

+----------+-------+------+-------------------+-----------+
| idsubbox | brand | size | content_idcontent | box_idbox |
+----------+-------+------+-------------------+-----------+
  1          Abcd    5.0     1                  13
  2          Abcd    5.0     1                  13
  3          Abcd    5.0     1                  13

So we have 3 different subboxes(1, 2, 3) of the same box(13). The problem is that with the configuration above it's not possible to keep creating subboxes inside a subbox, we would have to create a Subsubbox entity, Subsubsubbox and so on.

The question is, how can I create a Box inside a Box infinitely without having to create N entities? An inner box (the box inside a top box) should have the very same properties from the top box, but its values could differ, just like the dolls have different sizes.