How do i r etrieve users?

Give the following table:

I need to extract users who are in group 1 and 2, which means I only need to retrieve user 123. My query goes like the following:

with two_groups as (
select employee_id
from table1
where group in ('group1', 'group2')
group by 1
having max(group) <> min(group) and count(employee_id) = 2
)
select *
from two_groups
join table1 using (employee_id)

The reason that I am joining it back to the table1 is because I could not add the group and probability columns as a field in the "two_groups" subquery because I didn't want to group by them.

What Can I do to just extract the users being in just exactly two groups?

Thank you!