SQL that may be impossible to write

Question

I am currently using a 10.2.0.4 version Oracle Database.
I have a table that contains all of the employees with a REPORTS_TO column so you can tell which employee reports to whom. The data looks something like this:
POSITION_NBR EMP_NAME JOB_TITLE REPORTS_TO
1122 Boss, Ima Owner
5421 Mann, James Manager 1122
5621 Black, Mary Manager 1122
2201 Clark, Michael Supervisor 5421
6620 Reed, Roland Supervisor 5621
6890 Jackson, William Supervisor 5421
7220 Hansome, Jack Supervisor 5421
3342 Terry, Cherry Desktop 2201
6902 Butter, Pat Admin 2201
7365 Gonzales, Slyvia Admin 6890
7369 Knapp, Jason Sales 6890
7370 Fedric, Justin Sales 6890
7401 Blakeney, Albert Sales 6890
7422 Mora, Phillip Admin 7220
9880 Herrera, Milton Driver 7220
9882 Aguire, Fred Driver 7220
9900 Armijo, Randall Laborer 6620
9960 Watkins, Jack Laborer 6620
By looking at the data you can see that POSITION_NBR 1122 is the owner of the place and doesn't report to anyone. If you look down the REPORTS_TO column for 1122, you can see that there are two Manager's who report to the Owner because the 1122 is his position number.
The data above I just made up. The real data probably has 8 or 10 levels with hundreds of employees. I want to write an SQL where I can say show me all of the employee's that belong to a specific POSITION_NBR, no matter what the level and get back all of that person's employees. So, if I wanted to see 5621s employee's I would like to get back POSITION_NBRs: 6620, 9900, and 9960, because I want to include the subordinates. If you look at the data 6620 is the only person reporting to 5621, but 9900 and 9960 report to position 6620 so I want to include them.
I am really poor with Analytical Functions, but from what I see I cannot use them any way. I can write a correlated sub-query, but since I'm not sure how many levels I want, I'm not sure how I could write it to get back all of the appropriate people in one column anyway. I can do it with PL/SQL, but would really like an SQL Statement that I could use.
If I wanted to see all of William Jackson's employee's I would like to see POSITION_NBRs 7365, 7369, 7370, and 7401 come back. If I wanted to see all of Michael Clark's employees I would like to see POSITION_NBRs 3342 and 6902 come back. If I wanted to see Ima Boss's employee's I would like to see all of the POSITION_NBRs returned.
Is this possible to do with SQL or should I just stick with PL/SQL?
Any help is appreciated.
The scripts below can be used to create the example data:
create table example_table
(position_nbr number,
emp_name varchar2(40),
job_title varchar2(20),
reports_to number);
insert into example_table values(1122,'Boss, Ima','Owner','');
insert into example_table values(5421,'Mann, James','Manager','1122');
insert into example_table values(5621,'Black, Mary','Manager','1122');
insert into example_table values(2201,'Clark, Michael','Supervisor','5421');
insert into example_table values(6620,'Reed, Roland','Supervisor','5621');
insert into example_table values(6890,'Jackson, William','Supervisor','5421');
insert into example_table values(7220,'Hansome, Jack','Supervisor','5421');
insert into example_table values(3342,'Terry, Cherry','Desktop','2201');
insert into example_table values(6902,'Butter, Pat','Admin','2201');
insert into example_table values(7365,'Gonzales, Slyvia','Admin','6890');
insert into example_table values(7369,'Knapp, Jason','Sales','6890');
insert into example_table values(7370,'Fedric, Justin','Sales','6890');
insert into example_table values(7401,'Blakeney, Albert','Sales','6890');
insert into example_table values(7422,'Mora, Phillip','Admin','7220');
insert into example_table values(9880,'Herrera, Milton','Driver','7220');
insert into example_table values(9882,'Aguire, Fred','Driver','7220');
insert into example_table values(9900,'Armijo, Randall','Laborer','6620');
insert into example_table values(9960,'Watkins, Jack','Laborer','6620');
commit;
Thanks - mike

Answer 1

Thanks for posting the sample data.
From next time if you could format your post it will be much appreciated. Also spend some time reading the oracle manual. It's all documented there.
select * from example_table
start with position_nbr = 6890
connect by prior position_nbr = reports_to;Link for hierarchical queries
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/queries003.htm#sthref3132
http://tahiti.oracle.com
Regards
Raj