select distinct b.ID_Code, b.supply_start_date, b.supply_end_date, b.system_id
from (
 select ID_Code, max(supply_start_date) as max_dt
 from tmp_mmt_sup
 group by ID_Code) a
inner join tmp_mmt_sup b
on a.ID_Code=b.ID_Code and a.max_dt=b.SUPPLY_START_DATE;

ID_Code    Start        End          System
123        01-04-2018   30-04-2018   ABC
123        01-04-2018   30-04-2018   DEF