Hi Matthew,
Thanks for the inputs so far...
As mentioned in my main post I mapped it_chrg_item to et_item using ...
et_item = CORRESPONDING #( it_chrg_item MAPPING db_key = key ).
As mentioned by you to fill the mandt field I used
et_item = VALUE #( FOR <ls_item> IN et_item ( mandt= p_mandt) ).
However now all the other field in et_item are overwritten and only mandt field seems to be filled.
I need all the fields in et_item including mandt to be filled.
Additionally, is there a way of combining CORRESPONDING# and VALUE# into one construct ?