CHARINDEX ще ви помогне Справка
declare @temp table
(val nvarchar(77))
insert into @temp values ('SSS Pensioner Loan (C000000001)')
insert into @temp values ('SSS SSS Loan (C000000002) ')
insert into @temp values ('SSS Salary Loan (C000000007) ')
insert into @temp values ('SSS PAGIBIG Loan (C000000003) ')
SELECT
SUBSTRING(val,CHARINDEX('(', val) + 1,CHARINDEX(')', val) - CHARINDEX('(', val) - 1) as Val
from @temp