Oracle 18c

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CREATE TABLE a(
   SETID     VARCHAR(5) NOT NULL 
  ,SEL_GROUP VARCHAR(8) NOT NULL
);
begin
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_01DBA');
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_02DHM');
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_03DML');
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_03DMO');
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_05CAO');
INSERT INTO a(SETID,SEL_GROUP) VALUES ('KICAE','AA_05CGA');
end;
/
1 rows affected

CREATE TABLE b(
   SETID      VARCHAR(5) NOT NULL 
  ,COURSELIST INTEGER  NOT NULL
);
begin
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110011000);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110011200);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110011500);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110011530);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110021000);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110021200);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110021500);
INSERT INTO b(SETID,COURSELIST) VALUES ('KICAE',110021530);
end;
/
1 rows affected

select a.setid, a.sel_group, b.courselist
from (
    select a.*, row_number() over(partition by setid order by sel_group) rn
    from a
) a
inner join (
    select b.*, dense_rank() over(partition by setid order by substr(courselist, 1, 6)) rn
    from b
) b on a.setid = b.setid and a.rn = b.rn


SETID
SEL_GROUP
COURSELIST


KICAE
AA_01DBA
110011000

KICAE
AA_01DBA
110011200

KICAE
AA_01DBA
110011500

KICAE
AA_01DBA
110011530

KICAE
AA_02DHM
110021000

KICAE
AA_02DHM
110021200

KICAE
AA_02DHM
110021500

KICAE
AA_02DHM
110021530

SETID	SEL_GROUP	COURSELIST
KICAE	AA_01DBA	110011000
KICAE	AA_01DBA	110011200
KICAE	AA_01DBA	110011500
KICAE	AA_01DBA	110011530
KICAE	AA_02DHM	110021000
KICAE	AA_02DHM	110021200
KICAE	AA_02DHM	110021500
KICAE	AA_02DHM	110021530