Hierarchical Table - How To Get Data From Users

I have two table. Department is hierarchical table.

Department
--- id (int primary key)
--- name (varchar)
--- parent (int)

Users
--- Id
--- name
--- department_id

This query return all data from departments. But i cannot understand how get data from users

SELECT t1.name AS lvl1, t2.name as lvl2, t3.name as lvl3
FROM Department AS t1
LEFT JOIN Department AS t2 ON t2.parent = t1.id
LEFT JOIN Department AS t3 ON t3.parent = t2.id