Select one column into debit and credit
declare @t table (LEAD_CO_MNE int identity, CURRENCY varchar(10), AMOUNT_FCY int, AMOUNT_LCY int);
insert into @t (CURRENCY, AMOUNT_FCY, AMOUNT_LCY)
values ('KHR', 10, 20), ('KHR', -10, -20), ('KHR', 30, 40), ('other', 1, 2);

with cte as
(
SELECT [LEAD_CO_MNE]
      ,CASE
         WHEN CURRENCY &lt;&gt; 'KHR' THEN  AMOUNT_FCY
         ELSE AMOUNT_LCY
         END Amount --I want to split into type of amount debit or crdit
     ,CURRENCY
from @t
)

select [LEAD_CO_MNE], 
       CURRENCY,
       case when Amount &gt; 0 then Amount else 0 end as Credit,
       case when Amount &lt; 0 then Amount else 0 end as Debit
from cte;