Would something like this work?
(Obviously you can remove the row number part if your not putting it in a nsql query, thus not needing a unique value for id)
The replace part is because my system has / in one of the names of the lookup values, so i couldn't use it as a path marker...
SELECT
ROW_NUMBER() OVER (ORDER BY CMN.ID) RNUM
, CMN.ID Internal_ID
, CMN.LOOKUP_CODE Lookup_Code
, CAP.NAME Lookup_Name
, LTRIM(SYS_CONNECT_BY_PATH(REPLACE(CAP.NAME, '/', '\'), '/'),'/') Path
FROM CMN_LOOKUPS CMN
JOIN CMN_CAPTIONS_NLS CAP ON CMN.ID = CAP.PK_ID AND CAP.TABLE_NAME = 'CMN_LOOKUPS' AND CAP.LANGUAGE_CODE = 'en'
WHERE LEVEL > 1
CONNECT BY PRIOR CMN.LOOKUP_CODE = CMN.PARENT_LOOKUP_CODE
Hope it helps!
Chris