Postgres 10

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create table employees (
 employeeid int primary key,
 bossid int, 
 salary int, 
 hierarchy int
);

CREATE TABLE


insert into employees (employeeid, bossid, salary, hierarchy) values
  (20,          NULL,    10000,     0) 
, (10,          20,       4500,     1) 
, (50,          10,       3000,     2) 
, (70,          10,       1500,     2) 
, (40,          50,       1500,     3) 
, (60,          70,       2000,     3) 
, (30,          50,       1501,     3) 

INSERT 0 7


WITH RECURSIVE EmpCTE AS
(
    SELECT emp.employeeid, emp.salary, emp.bossid
    , 0 as Level
    , emp.employeeid AS BaseEmployeeId
    , emp.salary AS BaseEmployeeSalary
    FROM employees emp
    WHERE bossid IS NOT NULL
    
    UNION ALL
    
    SELECT mgr.employeeid, mgr.salary, mgr.bossid
    , cte.Level + 1
    , cte.BaseEmployeeId
    , cte.BaseEmployeeSalary
    FROM EmpCTE cte
    JOIN employees mgr
      ON mgr.employeeid = cte.bossid
    WHERE BaseEmployeeSalary*2 > cte.salary
)
SELECT 
  BaseEmployeeId AS EmployeeId
, BaseEmployeeSalary AS EmployeeSalary
, Level
, employeeid AS BossId
, salary AS BossSalary
FROM EmpCTE emp
WHERE BaseEmployeeSalary*2 <= salary
ORDER BY BaseEmployeeId


employeeid
employeesalary
level
bossid
bosssalary


10
4500
1
20
10000

30
1501
2
10
4500

40
1500
1
50
3000

50
3000
2
20
10000

60
2000
2
10
4500

70
1500
1
10
4500



SELECT 6

employeeid	employeesalary	level	bossid	bosssalary
10	4500	1	20	10000
30	1501	2	10	4500
40	1500	1	50	3000
50	3000	2	20	10000
60	2000	2	10	4500
70	1500	1	10	4500