У меня был некоторый успех с тем же выводом, что и у вас.
create table #table
(
CompanyID int,
CompanyName varchar(200),
Year int,
Quater int
)
insert into #table (CompanyID,CompanyName,Year,Quater)
VALUES
('1','Test1','2017','1'),
('1','Test1','2017','2'),
('1','Test1','2018','1'),
('1','Test1','2018','2'),
('2','Test2','2018','3'),
('2','Test2','2018','4')
SELECT CompanyID,CompanyName,Year,Quater
FROM
(
Select CompanyID,CompanyName,Year,Quater
, ROW_NUMBER() OVER(PARTITION BY CompanyID ORDER BY Year desc,Quater DESC)
as RowNum
from #table
) X WHERE RowNum = 1
drop table #table