Division:

 id |          name           | subdivision_of
----+-------------------------+----------------
  1 | Public Relations Bureau |
  2 | Division A              |              1
  3 | Division B              |              1
  4 | SubDivision 2 of A      |              2
  5 | SubDivision 2 of B      |              3

Employee:

 id |  name
----+--------
  1 | Irwin
  2 | Ernest

Position:

 id | name
----+-------
  1 | Head
  2 | Staff

Role:

 employee_id | division_id | position_id
-------------+-------------+-------------
           1 |           5 |           2
           2 |           4 |           1