Utilisez Listagg() en 11g ou WM_Concat() en 10g :
SELECT LISTAGG(TITLE_OF_DOC_SEC, ',') WITHIN GROUP (ORDER BY TRACKING_NUM) AS TITLE_OF_DOC_SEC
FROM your table
WHERE....
SELECT WM_CONCAT(TITLE_OF_DOC_SEC) AS TITLE_OF_DOC_SEC
FROM your table
WHERE....