Для этого вам понадобится рекурсивный cte:
WITH split_values ( username, values1, start1, end1 ) AS (
SELECT username, values1, 1, instr( values1, '|', 1 )
FROM table_name
UNION ALL
SELECT username, values1, end1 + 1, INSTR( values1, '|', end1 + 1 )
FROM split_values
WHERE end1 > 0
)
SELECT username,
CASE end1
WHEN 0 THEN SUBSTR( values1, start1 )
ELSE SUBSTR( values1, start1, end1 - start1 )
END AS values1
FROM split_values