DECLARE @Id int = your_UnitId
;WITH cte AS
(
SELECT a.Id, a.parentId, a.name
FROM customer a
WHERE Id = @Id
UNION ALL
SELECT a.Id, a.parentid, a.Name
FROM customer a JOIN cte c ON a.parentId = c.id
)
SELECT parentId, Id, name
FROM cte
Démo sur SQLFiddle