MySQL 8.0

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create table transform_data_1 (`Date` date, 
                    brand varchar(20),
                    Market varchar(20),
                    CONV varchar(20),
                    PgmGRPs int);
insert into transform_data_1 values('2020-01-01', 'ABC' , 'MTL', 'conv.', 80 );
insert into transform_data_1 values('2020-01-01', 'ABC' , 'MTL', 'Spec.', 20 );
insert into transform_data_1 values('2020-01-01', 'ABC' , 'TO', 'conv.', 70 );
insert into transform_data_1 values('2020-01-01', 'ABC' , 'TO', 'Spec.', 40 );
insert into transform_data_1 values('2020-01-02', 'DEF' , 'TO', 'conv.', 80 );
insert into transform_data_1 values('2020-01-02', 'DEF' , 'TO', 'Spec.', 20 );
select tab.`Date`
       , tab.brand
       , tab.market
       , Conv_PgmGRPs
       , Spec_PgmGRPs 
       , Total_PgmGRPs
       , ROUND(Conv_PgmGRPs / (Conv_PgmGRPs + Spec_PgmGRPs),2) as 'Conv. Ratio'
       , ROUND(Spec_PgmGRPs / (Conv_PgmGRPs + Spec_PgmGRPs),2) as 'Spec. Ratio'
from (select `Date`
       , brand
       , Market
       , (select sum(PgmGRPs)  
          from transform_data_1 t1 
          where t.`Date` = t1.`Date`
          and  t.brand = t1.brand
          and t.Market = t1.Market
          and t1.CONV = 'conv.') Conv_PgmGRPs
       , (select sum(PgmGRPs)  
          from transform_data_1 t1 
          where t.`Date` = t1.`Date`
          and  t.brand = t1.brand
          and t.Market = t1.Market
          and t1.CONV = 'Spec.') Spec_PgmGRPs
       , sum(PgmGRPs) Total_PgmGRPs
from transform_data_1 t
group by `Date`
       , brand
       , Market) tab


Date
brand
market
Conv_PgmGRPs
Spec_PgmGRPs
Total_PgmGRPs
Conv. Ratio
Spec. Ratio


2020-01-01
ABC
MTL
80
20
100
0.80
0.20

2020-01-01
ABC
TO
70
40
110
0.64
0.36

2020-01-02
DEF
TO
80
20
100
0.80
0.20

Date	brand	market	Conv_PgmGRPs	Spec_PgmGRPs	Total_PgmGRPs	Conv. Ratio	Spec. Ratio
2020-01-01	ABC	MTL	80	20	100	0.80	0.20
2020-01-01	ABC	TO	70	40	110	0.64	0.36
2020-01-02	DEF	TO	80	20	100	0.80	0.20