SQL> drop table hierarchy
  2  /

Table dropped.

SQL> create table hierarchy (id number primary key, mgr_id number
  2  , final number);

Table created.

SQL> alter table hierarchy add constraint mgr_fk
  2  foreign key (mgr_id) references hierarchy (id);

Table altered.

SQL> insert into hierarchy values(106, null, null);

1 row created.

SQL> insert into hierarchy values(105, null, null);

1 row created.

SQL> insert into hierarchy values(104, 105, null);

1 row created.

SQL> insert into hierarchy values(103, 104, null);

1 row created.

SQL> insert into hierarchy values(102, 103, null);

1 row created.

SQL> insert into hierarchy values(101, 102, null);

1 row created.

SQL> commit;

Commit complete.

SQL> update hierarchy h3
  2  set h3.final = (
  3  select substr((select max(to_char(level, 'fm0000')||h2.id)
  4                from   hierarchy h2
  5                start  with h2.id = h1.id
  6                connect by prior h2.mgr_id = h2.id), 5)
  7  from   hierarchy h1
  8  where  h1.id = h3.id)
  9  /

6 rows updated.

SQL> select * from hierarchy;

        ID     MGR_ID      FINAL                                                
---------- ---------- ----------                                                
       106                   106                                                
       105                   105                                                
       104        105        105                                                
       103        104        105                                                
       102        103        105                                                
       101        102        105                                                

6 rows selected.

SQL> spool off