MySQL 8.0

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CREATE TABLE table1
    (`title` varchar(29))
;
    
INSERT INTO table1
    (`title`)
VALUES
    ('sales,marketing,operations'),
    ('sales'),
    ('operations,project management'),
    ('sales,operations')
;
SELECT
  DISTINCT SUBSTRING_INDEX(SUBSTRING_INDEX(title, ',', n.digit+1), ',', -1) title
FROM
  table1
  INNER JOIN
  (SELECT 0 digit UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3  UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6) n
  ON LENGTH(REPLACE(title, ',' , '')) <= LENGTH(title)-n.digit;


title


sales

operations

marketing

project management


SELECT
  SUBSTRING_INDEX(SUBSTRING_INDEX(title, ',', n.digit+1), ',', -1) title
FROM
  table1
  INNER JOIN
  (SELECT 0 digit UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3  UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6) n
  ON LENGTH(REPLACE(title, ',' , '')) <= LENGTH(title)-n.digit;


title


sales

sales

operations

sales

marketing

project management

operations

operations


SELECT
  SUBSTRING_INDEX(SUBSTRING_INDEX(title, ',', n.digit+1), ',', -1) title, Count(*)
FROM
  table1
  INNER JOIN
  (SELECT 0 digit UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3  UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6) n
  ON LENGTH(REPLACE(title, ',' , '')) <= LENGTH(title)-n.digit
  GROUP BY SUBSTRING_INDEX(SUBSTRING_INDEX(title, ',', n.digit+1), ',', -1);


title
Count(*)


sales
3

operations
3

marketing
1

project management
1