pd        stm    salesincrease
Chamomile   Central 801
Caffe Mocha Central 752
Earl Grey   Central 725
Colombian   East    975
Lemon       East    573
RegEspresso East    531
Caffe Mocha East    356
Lemon       West    667
DeEspresso  West    664
Colombian   West    628
Darjeeling  West    623

select  stm, pd, max(salesincrease) as maxsales from
table
group by stm, pd;

select  stm, max(salesincrease) as maxsales from
table
group by stm;

pd        stm    salesincrease
Chamomile   Central 801
Colombian   East    975
Lemon       West    667

select pd, stm, salesincrease
from (select t.*, row_number() over (partition by pd order by salesincrease desc) as seqnum
      from table t
     ) t
where seqnum = 1;