Recur

WITH EmpSup as((
SELECT e.EmployeeID EmpID, e.LastName EmpName,NULL SupID, NULL SupName  FROM Employees e, Employees e2
WHERE e.ReportsTo IS NULL
UNION
SELECT e.EmployeeID EmpID, e.LastName EmpName,e2.EmployeeID SupID, e2.LastName SupName  FROM Employees e, Employees e2
WHERE e.ReportsTo = e2.EmployeeID)
UNION ALL
SELECT e.EmployeeID EmpID, e.LastName EmpName,e2.SupID SupID, e2.SupName SupName  FROM Employees e, EmpSup e2
WHERE e.ReportsTo = e2.EmpID AND SupID IS NOT NULL
)

SELECT * FROM EmpSup
ORDER BY SupID