How can I join the same data for different columns?

I am sstruggling to make a query to join the corresponding replacing the IDs. I have two tables USERS and CONNECTIONS.

Users:

user_id  first_name
--------------------
     3   Jim
     4   Pam
     5   Michael

Connections:

user_id  friend_id
--------------------
     3   4
     4   3
     4   5
     5   4

In Connections both columns includes the user_id from Users to represent the connection between the people. I need the result like below:

user     friend
----------------
Jim       Pam
Pam       Jim
Pam       Michael
Michael   Pam

Answer

Joining Connections table with Users tables give the expected result.

By using U1.user_id = C.user_id to get the user and using U2.user_id = C.friend_id to get the friend values.

SELECT U1.first_name AS user, U2.first_name AS friend
FROM Connections C
JOIN Users U1 ON U1.user_id = C.user_id
JOIN Users U2 ON U2.user_id = C.friend_id

Demo on db<>fiddle

output:

user        friend
--------------------
Jim         Pam
Pam         Jim
Pam         Michael
Michael     Pam