SQLite 3.27

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CREATE TABLE IF NOT EXISTS TABLE_NAME (
	ID INTEGER,
	Todolist TEXT,
	Tags TEXT,
	PRIMARY KEY(ID AUTOINCREMENT)
);
INSERT INTO TABLE_NAME (ID,Todolist,Tags) VALUES 
 (1,'Buy groceries','Mom'),
 (2,'Play badminton','Sister'),
 (3,'Wash clothes','Dad'),
 (4,'Study','Me'),
 (5,'Holiday trip','Me, Mom, Dad, Sister');
WITH
  list(tag) AS (SELECT 'Me,Mom'), 
  cte(tag, value) AS (
    SELECT SUBSTR(tag, 1, INSTR(tag || ',', ',') - 1),
           SUBSTR(tag, INSTR(tag || ',', ',') + 1)
	FROM list	   
    UNION ALL
    SELECT SUBSTR(value, 1, INSTR(value || ',', ',') - 1),
           SUBSTR(value, INSTR(value || ',', ',') + 1)  
    FROM cte
    WHERE LENGTH(value) > 0  
  )
SELECT t.* 
FROM TABLE_NAME t 
WHERE EXISTS (
  SELECT 1 FROM cte c
  WHERE ',' || REPLACE(t.Tags, ', ', ',') || ',' LIKE '%,' || c.tag || ',%' 
)


ID
Todolist
Tags


1
Buy groceries
Mom

4
Study
Me

5
Holiday trip
Me, Mom, Dad, Sister