Hi Monika
Did you try calling BUPA_ROLES_GET_2 , by using the empty parameter of iv_date like , not sure but that might help
CALL FUNCTION 'BUPA_ROLES_GET_2'
EXPORTING
iv_partner = iv_partner_id
iv_date = ''
TABLES
et_partnerroles = lt_partnerroles
et_return = lt_return.
or at the last case you can do a select on but100
/Hasan