You can find it using the following co-related subquery:
SELECT * FROM Employee E1 WHERE n-1 =
(SELECT COUNT(DISTINCT Salary_amount) FROM Employee E2 WHERE E1.Salary_amount > E2.Salary_Amount)
Where n is the level you want to find. for example in your case, replace n with 3.
did you try with a window function ?
-- Partition by Department
qualify row_number() over(partition by Department order by Salary_Amount) < n
-- NO Partition at all
qualify row_number() over(order by Salary_Amount) < n