title: Could you help me to solve this simple join issue?i am new to sql so no idea what is wrong with this
body: <pre><code>SELECT LEVEL_A.VALUE,LEVEL_B.VALUE,LEVEL_C.VALUE,LEVEL_C.VALUE
    FROM CUSP_VALUE_LIST_HEADER H
    JOIN CUSP_VALUE_LIST_ITEM LEVEL_C
      ON H.VALUE_LIST_HEADER_NO = LEVEL_C.VALUE_LIST_HEADER_NO
    JOIN (SELECT I.VALUE, I.DESCRIPTION
            FROM CUSP_VALUE_LIST_HEADER H
            JOIN CUSP_VALUE_LIST_ITEM I
              ON H.VALUE_LIST_HEADER_NO = I.VALUE_LIST_HEADER_NO
           WHERE H.CAPTION = 'SERVER_ENTITY'
             AND LOWER(NVL(I.DESCRIPTION, ' ')) NOT LIKE '%disabled%') LEVEL_A
      ON LEVEL_A.VALUE = REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 1)
      
    JOIN (SELECT I.VALUE, I.DESCRIPTION
            FROM CUSP_VALUE_LIST_HEADER H
            JOIN CUSP_VALUE_LIST_ITEM I
              ON H.VALUE_LIST_HEADER_NO = I.VALUE_LIST_HEADER_NO
           WHERE H.CAPTION = 'PurchaseType'
             AND LOWER(NVL(I.DESCRIPTION, ' ')) NOT LIKE '%disabled%') LEVEL_B
      ON LEVEL_B.VALUE = REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 1) || '#' ||
         REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 2)
   WHERE H.CAPTION = 'PurchaseSubCategoryList'
     AND LOWER(NVL(LEVEL_C.DESCRIPTION, ' ')) NOT LIKE '%disabled%'
  
    JOIN (SELECT I.VALUE, I.DESCRIPTION
            FROM CUSP_VALUE_LIST_HEADER H
            JOIN CUSP_VALUE_LIST_ITEM I
              ON H.VALUE_LIST_HEADER_NO = I.VALUE_LIST_HEADER_NO
           WHERE H.CAPTION = 'PurchaseCategoryList'
          AND LOWER(NVL(I.DESCRIPTION, ' ')) NOT LIKE '%disabled%') LEVEL_D
      ON LEVEL_D.VALUE = REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 1) || '#' ||
          REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 2) || '#' ||  REGEXP_SUBSTR(LEVEL_C.VALUE, '[^#]+', 1, 3)
   WHERE H.CAPTION = 'PurchaseSubCategoryList'
     AND LOWER(NVL(LEVEL_C.DESCRIPTION, ' ')) NOT LIKE '%disabled%'
   ORDER BY LEVEL_C.VALUE ASC;
  </code></pre>