Hi,
FIELD-SYMBOLS <FS_WA> LIKE LINE OF IT_ITAB2.
SORT IT_ITAB2 BY BELNR DESCENDING.
DELETE ADJACENT DUPLICATES FROM IT_ITAB2 COMPARING BELNR.
LOOP AT it_tab2 ASSIGNING <FS_WA>.
MODIFY it_tab FROM <FS_WA> TRANSPORTING kunnr bldat xblnr WHERE belnr = <FS_WA>-BELNR..
ENDLOOP.
REFRESH: it_tab2.
Regards,
Ashish