Concatenar el valor de la segunda columna si el valor de la primera columna es el mismo

Use Listagg() en 11g o 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....