Попробуйте это:
declare @tbl table (TIPE varchar(5), NILAI int);
insert into @tbl values
('PSX', 10),
('GE', 10),
('EG', 10),
('SX', 20),
('SXL', 20),
('SZ', 20);
select NILAI,
(select TIPE + '/' from @tbl where t.NILAI = NILAI for xml path('')) [TIPE]
from @tbl t
group by NILAI
--for sql server 2017 or newer
select NILAI, string_agg(TIPE, '/') TIPE
from @tbl
group by NILAI