Expand a recursive hierarchy

drop table employee;
drop sequence eid;
create sequence Eid start with 100 increment by 1;

create table employee(
  empid int primary key default next value for eid,
  fname varchar(50),
  managerid int
);

insert into employee(fname, managerid) values('Joseph', null),
('Brigham',100),
('John',100),
('Wilfred',101),
('Lorenzo',101),
('Heber',104),
('Harold',105);


select * from employee;

select e.fname , e1.fname as level1, e2.fname as level2, e3.fname as level3
from employee e
left outer join employee e1 on e.managerid=e1.empid
left outer join employee e2 on e1.managerid=e2.empid
left outer join employee e3 on e2.managerid=e3.empid