Oracle 21c

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ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
CREATE TABLE company (cidgen, nation) AS
SELECT 'Acme Corporation',     'AA' FROM DUAL UNION ALL
SELECT 'Octan',                'CC' FROM DUAL UNION ALL
SELECT 'Umbrella Corporation', 'BB' FROM DUAL UNION ALL
SELECT 'Wayne Enterprises',    'BB' FROM DUAL;
4 rows affected

CREATE TABLE nation_lookup (code) AS
SELECT 'AA' FROM DUAL UNION ALL
SELECT 'BB' FROM DUAL UNION ALL
SELECT 'CC' FROM DUAL;
3 rows affected

CREATE TABLE /*RAN.*/OA_REQUEST_RESPONSE_STATUS (cidgen, response_status, response_update_stamp) AS
SELECT 'Acme Corporation',     'FailedRequest', SYSDATE FROM DUAL UNION ALL
SELECT 'Octan',                'FailedRequest', SYSDATE FROM DUAL UNION ALL
SELECT 'Umbrella Corporation', 'FailedRequest', SYSDATE FROM DUAL UNION ALL
SELECT 'Wayne Enterprises',    'FailedRequest', SYSDATE FROM DUAL
4 rows affected

CREATE TYPE string_list IS TABLE OF VARCHAR2(200);
DECLARE
  p_nation STRING_LIST := STRING_LIST('AA', 'BB', 'CC');
  p_lastrundate VARCHAR2(20) := '01-JAN-1970 00:00:00';
BEGIN
  DBMS_OUTPUT.PUT_LINE('CIDGEN' || '||' || 'NATION');
  FOR rec IN (
    SELECT B.CIDGEN,
           B.NATION
    FROM   COMPANY B
           INNER JOIN NATION_LOOKUP C
           ON B.NATION = C.CODE
           INNER JOIN TABLE(p_nation) n
           ON B.nation = n.COLUMN_VALUE
    WHERE  B.CIDGEN IN (
             SELECT CIDGEN
             FROM   /*RAN.*/OA_REQUEST_RESPONSE_STATUS
             WHERE  RESPONSE_STATUS = 'FailedRequest'
             AND    RESPONSE_UPDATE_STAMP >=
                      TO_DATE(p_lastrundate, 'DD-MON-YYYY HH24:MI:SS')
          )
  )
  LOOP
    DBMS_OUTPUT.PUT_LINE(rec.CIDGEN || '||' || rec.NATION);
  END LOOP;
END;
/
1 rows affected

dbms_output:
CIDGEN||NATION
Acme Corporation||AA
Octan||CC
Umbrella Corporation||BB
Wayne Enterprises||BB