Oracle 18c

By using db<>fiddle, you agree to license everything you submit by Creative Commons CC0.
CREATE TABLE table_name (
  job_num     VARCHAR2(20),
  job_stage   VARCHAR2(20),
  "TIMESTAMP" DATE
);
INSERT INTO table_name ( job_num, job_stage, "TIMESTAMP" )
SELECT 'job_1', 'waiting', to_date('1/28/2020 11:51', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'waiting', to_date('1/28/2020 11:52', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'waiting', to_date('1/28/2020 11:53', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'running', to_date('1/28/2020 11:54', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'running', to_date('1/28/2020 11:55', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'running', to_date('1/28/2020 11:56', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'running', to_date('1/28/2020 11:57', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'finishing', to_date('1/28/2020 11:58', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_1', 'finishing', to_date('1/28/2020 11:59', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'waiting', to_date('1/28/2020 11:52', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'waiting', to_date('1/28/2020 11:53', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'waiting', to_date('1/28/2020 11:54', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'waiting', to_date('1/28/2020 11:55', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'waiting', to_date('1/28/2020 11:56', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'running', to_date('1/28/2020 11:57', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'running', to_date('1/28/2020 11:58', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'running', to_date('1/28/2020 11:59', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'running', to_date('1/28/2020 12:00', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'finishing', to_date('1/28/2020 12:01', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'finishing', to_date('1/28/2020 12:02', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'finishing', to_date('1/28/2020 12:03', 'MM/DD/YYYY HH24:MI') from dual UNION ALL
SELECT 'job_2', 'finishing', to_date('1/28/2020 12:04', 'MM/DD/YYYY HH24:MI') from dual;
22 rows affected

ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD HH24:MI:SS';
SELECT *
FROM   table_name
PIVOT(
  MIN( "TIMESTAMP" ) AS min,
  MAX( "TIMESTAMP" ) AS max
  FOR job_stage IN (
    'waiting' AS waiting,
    'running' AS running,
    'finishing' AS finishing
  )
)


JOB_NUM
WAITING_MIN
WAITING_MAX
RUNNING_MIN
RUNNING_MAX
FINISHING_MIN
FINISHING_MAX


job_2
2020-01-28 11:52:00
2020-01-28 11:56:00
2020-01-28 11:57:00
2020-01-28 12:00:00
2020-01-28 12:01:00
2020-01-28 12:04:00

job_1
2020-01-28 11:51:00
2020-01-28 11:53:00
2020-01-28 11:54:00
2020-01-28 11:57:00
2020-01-28 11:58:00
2020-01-28 11:59:00


SELECT job_num,
       MIN( CASE job_stage WHEN 'waiting' THEN "TIMESTAMP" END ) AS waiting_min,
       MAX( CASE job_stage WHEN 'waiting' THEN "TIMESTAMP" END ) AS waiting_max,
       MIN( CASE job_stage WHEN 'running' THEN "TIMESTAMP" END ) AS running_min,
       MAX( CASE job_stage WHEN 'running' THEN "TIMESTAMP" END ) AS running_max,
       MIN( CASE job_stage WHEN 'finishing' THEN "TIMESTAMP" END ) AS finishing_min,
       MAX( CASE job_stage WHEN 'finishing' THEN "TIMESTAMP" END ) AS finishing_max
FROM   table_name
GROUP BY job_num


JOB_NUM
WAITING_MIN
WAITING_MAX
RUNNING_MIN
RUNNING_MAX
FINISHING_MIN
FINISHING_MAX


job_2
2020-01-28 11:52:00
2020-01-28 11:56:00
2020-01-28 11:57:00
2020-01-28 12:00:00
2020-01-28 12:01:00
2020-01-28 12:04:00

job_1
2020-01-28 11:51:00
2020-01-28 11:53:00
2020-01-28 11:54:00
2020-01-28 11:57:00
2020-01-28 11:58:00
2020-01-28 11:59:00
JOB_NUM	WAITING_MIN	WAITING_MAX	RUNNING_MIN	RUNNING_MAX	FINISHING_MIN	FINISHING_MAX
job_2	2020-01-28 11:52:00	2020-01-28 11:56:00	2020-01-28 11:57:00	2020-01-28 12:00:00	2020-01-28 12:01:00	2020-01-28 12:04:00
job_1	2020-01-28 11:51:00	2020-01-28 11:53:00	2020-01-28 11:54:00	2020-01-28 11:57:00	2020-01-28 11:58:00	2020-01-28 11:59:00