Full recursive employee-boss relation in SQL Server

Question

I need to get the name of all of the employees that depends of a person directly or indirectly. Using the query in this example (from https://rextester.com/WGVRGJ67798),

create table employee(
id int not null,
employee varchar(10) not null,
boss int null    
)

insert into employee values
(1,'Anna',null),
(2,'Bob',1),
(3,'Louis',1),
(4,'Sara',2),
(5,'Sophie',2),
(6,'John',4);

with boss as (
     select id, employee, boss, cast(null as varchar(10)) as name
     from employee 
     where boss is null
    
     union all 
    
     select e.id, e.employee, b.id, b.employee
     from employee e 
     join boss b on b.id = e.boss
 )

select * from boss

I can get this result:

However, I need to see this:

It would be like showing all the possible relations between a person an all of those employees "below" him or her.

Answer 1

You can reverse the logic: instead of starting from the boss (the root) and going towards employees (the leafs), you could start from the leafs and walk toward the root. This lets you generate the intermediate relations as you go:

with cte as (
     select e.id, e.employee, e.boss, b.employee name, b.boss new_boss
     from employee e
     left  join employee b on b.id = e.boss
     union all 
     select c.id, c.employee, c.new_boss, e.employee, e.boss
     from cte c 
     join employee e on e.id = c.new_boss
)
select id, employee, boss, name 
from cte
order by id, boss

Demo on DB Fiddle:

id | employee | boss | name
-: | :------- | ---: | :---
 1 | Anna     | null | null
 2 | Bob      |    1 | Anna
 3 | Louis    |    1 | Anna
 4 | Sara     |    1 | Anna
 4 | Sara     |    2 | Bob 
 5 | Sophie   |    1 | Anna
 5 | Sophie   |    2 | Bob 
 6 | John     |    1 | Anna
 6 | John     |    2 | Bob 
 6 | John     |    4 | Sara