Oracle 18c

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CREATE TABLE electric_jobs ( event_id, troublequeue, begindatetime ) AS
SELECT  1, 'TM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  2, 'DL', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  3, 'DL', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  4, 'DL', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  5, 'AMI/STPR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  6, 'PM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  7, 'PM,CR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  8, 'DL', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT  9, 'TM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 10, 'AMI/STPR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 11, 'TM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 12, 'AMI/STPR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 13, 'AMI/STPR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 14, 'PM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 15, 'AMI/STPR', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 16, 'PM', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 17, 'MS', DATE '2021-01-01' FROM DUAL UNION ALL
SELECT 18, 'TOCY, TCN, TT, DL, POLE', DATE '2021-01-01' FROM DUAL;

18 rows affected

WITH trouble_ids ( id, HeldJobType ) AS (
  SELECT 'DL', 'Distribution Line Crew' FROM DUAL UNION ALL
  SELECT 'MS', 'Service Crew' FROM DUAL UNION ALL
  SELECT 'TM', 'Troubleman' FROM DUAL UNION ALL
  SELECT 'TT', 'Tree Crew' FROM DUAL UNION ALL
  SELECT 'POLE', 'Pole Job' FROM DUAL UNION ALL
  SELECT 'XFMR', 'Xfmr Job' FROM DUAL UNION ALL
  SELECT 'TOC', 'Tennesee One Call' FROM DUAL
),
job_ids ( event_id, troublequeue, job_id, lvl, max_lvl ) AS (
  SELECT event_id,
         troublequeue,
         REGEXP_SUBSTR( troublequeue, '[A-Z]+', 1, 1, 'i' ),
         1,
         REGEXP_COUNT( troublequeue, '[A-Z]+', 1, 'i' )
  FROM   electric_jobs
  WHERE  BeginDateTime BETWEEN DATE '2021-01-01' AND DATE '2021-02-01'
UNION ALL
  SELECT event_id,
         troublequeue,
         REGEXP_SUBSTR( troublequeue, '[A-Z]+', 1, lvl + 1, 'i' ),
         lvl + 1,
         max_lvl
  FROM   job_ids
  WHERE  lvl < max_lvl
)
SELECT COALESCE( t.HeldJobType, 'Other' ) AS HeldJobType,
       COUNT( e.event_id )
FROM   job_ids e
       LEFT OUTER JOIN trouble_ids t
       ON ( e.job_id = t.id )
GROUP BY
       COALESCE( t.HeldJobType, 'Other' );

HELDJOBTYPE	COUNT(E.EVENT_ID)
Distribution Line Crew	5
Pole Job	1
Other	17
Tree Crew	1
Service Crew	1
Troubleman	3