How to fetch all companies under a company if many affiliates are present - DB2

G007 AFFILATES HOULD RETURN ALL DIRECT SUB AND SUB TO SUB LEVEL AFFILIATES.
CAN BE TO NTH LEVEL

HOW TO QUERY in DB2?

AREVA_COMPANIES
---------------------------
COMPANY_CODE|AFFILIATE_CODE
G007        |K001
G007        |K002
G007        |K003
G007        |K004
K001        |K010
K001        |K011
K001        |K012
K002        |K020
K002        |K031
K004        |K067

WITH ALL_AFFILIATES(COMPANY_CODE,AFFILIATE_CODE) AS
(
 SELECT COMPANY_CODE, AFFILIATE_CODE
 FROM   AREVA_COMPANIES
 WHERE  COMPANY_CODE = 'G007'
 UNION ALL
 SELECT B.COMPANY_CODE, B.AFFILIATE_CODE
 FROM   AREVA_COMPANIES B , ALL_AFFILIATES A
 WHERE  B.COMPANY_CODE = A.AFFILIATE_CODE
)
SELECT COMPANY_CODE, AFFILIATE_CODE
FROM ALL_AFFILIATES