Db2 11.1

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE t(
   ID           INTEGER  NOT NULL
  ,SERVICE_TYPE VARCHAR(18) NOT NULL
  ,CNT          INTEGER  NOT NULL
);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'SACCOS',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'RETAIL_SME',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'TRANS_LOGISTIC',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'HEALTHCARE',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'ENERGY',7);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'NGO',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'TECH_SERVICES',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'BUSINESS_SERVICES',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'RELIGIOUS',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'INSURANCE',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'EDUCATION',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'MICROFINANCE',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'LOAN_REP_COUNT',2);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'WATER_BILL',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'PAY_TV',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'MERCHPAY_OP',1);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'MERCHPAY_AM',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'BETTING',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'AMTk_BUNDLE',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'AMTK_AIRTIME_RECH',1);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'ELECTRICITY_BILL',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'W2B',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'P2P_UNREG',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'P2P_OPTK',1);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'P2P_AMTK',1);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'CASHOUT',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'IMT',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'AGRICULTURE',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'AVIATION',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'SPORTS',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'CONSTRUCTION',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'HORECA',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'AGGREGATOR',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'MEDIA',0);
INSERT INTO t(ID,SERVICE_TYPE,CNT) VALUES (12345678,'FMCG',0);
select id,
  listagg(case when dr = 1 then service_type end, ',') as first,
  listagg(case when dr = 2 then service_type end, ',') as second,
  listagg(case when dr = 3 then service_type end, ',') as third
from (
  select t.*, dense_rank() over(partition by id order by cnt desc) as dr
  from t where cnt > 0  
) x
group by id


ID
FIRST
SECOND
THIRD


12345678
ENERGY
LOAN_REP_COUNT
MERCHPAY_OP,AMTK_AIRTIME_RECH,P2P_OPTK,P2P_AMTK