Multiple subqueries in columns with joins to return multiple rows
why you need use subqueries ?

You can use joins for get data

SELECT u.name AS user, d.name AS departement, m.year
FROM main AS m
INNER JOIN department AS d ON m.departement_id = d.id
INNER JOIN users AS u ON m.user_id = u.id
;


I created a sample fidle http://sqlfiddle.com/#!9/74a4e2/1