activeman님께서 알려주신 테이블을 이용해 아래처럼 수정을 하니 STLAL의 값은 가져올 수 있었습니다.

그런데 STLAL = '02', '03' 일때는 'CS_BOM_EXPLOSION'을 돌아도 결과값은 나오지 않습니다.

분명히 BOM은 존재하는데... 제가 무엇을 빼먹은 부분이 있는가요?

*---------------------------------------------------------------------*
*      Form  BOM_EXP
*---------------------------------------------------------------------*
FORM BOM_EXP.
  REFRESH : IT_01, IT_05.
  CLEAR : IT_01, IT_05.

  SELECT *
  INTO CORRESPONDING FIELDS OF TABLE IT_05 " 추가
  FROM MAST " 추가
    WHERE MAST~MATNR IN S_MATNR " 추가
      AND MAST~WERKS IN S_WERKS. " 추가

  LOOP AT IT2_01. " 추가
    LOOP AT IT_05 WHERE MATNR = IT2_01-MATNR. " 추가
      IT2_01-STLAL = IT_05-STLAL. " 추가
      MODIFY IT2_01. " 추가
    ENDLOOP. " 추가
  ENDLOOP. " 추가

  LOOP AT IT2_01.
    CLEAR : TEMP_STBP.
    READ TABLE IT2_01 INDEX SY-TABIX.
    WRITE IT2_01-WERKS TO PA_WERKS.
    WRITE IT2_01-MATNR TO PA_MATNR.
    WRITE IT2_01-STLAL TO PA_STLAL.

    IT_01-MATNR      = IT2_01-MATNR.
    IT_01-MAKTX      = IT2_01-MAKTX.
    IT_01-MTART      = IT2_01-MTART.
    IT_01-WERKS      = IT2_01-WERKS.
    IT_01-GI_03_QTY  = IT2_01-GI_03_QTY.
    IT_01-MEINS      = IT2_01-MEINS.
    IT_01-GI_03_FACT = IT2_01-GI_03_FACT.
    IT_01-WAERS      = IT2_01-WAERS.
    IT_01-STUFE      = '0'.
    IT_01-STLAL      = IT2_01-STLAL.
    IT_01-MATNR_C    = IT2_01-MATNR.
    APPEND IT_01.

    PERFORM BOM_EXP1 TABLES IT_01
            USING PA_MATNR PA_WERKS PA_STLAL SY-DATUM CHANGING LAST.
  ENDLOOP.

ENDFORM.

*---------------------------------------------------------------------*
*      Form  BOM_EXP
*---------------------------------------------------------------------*
FORM BOM_EXP1 TABLES P_BOM_EXPLODED STRUCTURE IT_01
     USING P_IDNRK P_WERKS P_STLAL P_DATUV CHANGING P_LAST.

  CALL FUNCTION 'CS_BOM_EXPLOSION'
    EXPORTING
      CAPID = 'PP01'
      DATUV = P_DATUV
      MTNRV = P_IDNRK
      WERKS = P_WERKS
      STLAL = P_STLAL
      MEHRS = 'X'
    TABLES
      STBP = IT_STBP
      STBD = IT_STBD
      STBE = IT_STBE
      STBK = IT_STBK
      STBM = IT_STBM
      STBT = IT_STBT
    EXCEPTIONS
      ALT_NOT_FOUND         = 1
      CALL_INVALID          = 2
      MISSING_AUTHORIZATION = 4
      NO_BOM_FOUND          = 5
      NO_PLANT_DATA         = 6
      NO_SUITABLE_BOM_FOUND = 7
      CONVERSION_ERROR      = 8
      OTHERS                = 9.

    LOOP AT IT_STBP.
      TEMP_STBP-OBJNR = IT_STBP-OBJNR.
      TEMP_STBP-WERKS = P_WERKS.
      TEMP_STBP-STLAL = IT_STBP-STLAL.
      APPEND TEMP_STBP.
    ENDLOOP.

    IF SY-SUBRC <> 0.
      P_LAST = 'X'.
    ELSE.
      LOOP AT TEMP_STBP.
        IT_01-MATNR      = IT2_01-MATNR.
        IT_01-MAKTX      = IT2_01-MAKTX.
        IT_01-MTART      = IT2_01-MTART.
        IT_01-WERKS      = IT2_01-WERKS.
        IT_01-GI_03_QTY  = IT2_01-GI_03_QTY.
        IT_01-MEINS      = IT2_01-MEINS.
        IT_01-GI_03_FACT = IT2_01-GI_03_FACT.
        IT_01-WAERS      = IT2_01-WAERS.
        IT_01-STUFE      = ''.
        IT_01-STLAL      = TEMP_STBP-STLAL.
        IT_01-MATNR_C    = TEMP_STBP-OBJNR.
        APPEND IT_01.
      ENDLOOP.

      LOOP AT TEMP_STBP. " 추가
        LOOP AT IT_05 WHERE MATNR = TEMP_STBP-OBJNR. " 추가
          TEMP_STBP-OBJNR = IT_05-MATNR. " 추가
          TEMP_STBP-WERKS = IT_05-WERKS. " 추가
          TEMP_STBP-STLAL = IT_05-STLAL. " 추가
          COLLECT TEMP_STBP. " 추가
        ENDLOOP. " 추가
      ENDLOOP. " 추가

      DELETE TEMP_STBP WHERE STLAL = '01'.
      DELETE TEMP_STBP WHERE STLAL = ''.

      LOOP AT TEMP_STBP.
        READ TABLE TEMP_STBP INDEX SY-TABIX.
        WRITE TEMP_STBP-WERKS TO PA_WERKS.
        WRITE TEMP_STBP-OBJNR TO PA_MATNR.
        WRITE TEMP_STBP-STLAL TO PA_STLAL.

        PERFORM BOM_EXP1 TABLES P_BOM_EXPLODED
                USING PA_MATNR PA_WERKS PA_STLAL P_DATUV CHANGING P_LAST.

        CLEAR P_LAST.
      ENDLOOP.
    ENDIF.
ENDFORM.