Get all non-empty rows from one column and then get all matching rows for those values

I've built a program that converts an Excel sheet containing my departments schedule to a SQL table. We always work in pairs so I want to be able to check all my shifts and what person I'll be working with for those shifts.
Table structure is, where T, K and N are the different shifts:

If I'm Jim in the table above I want to be able to get a response for 2025-04-14 like:

And for 2025-04-15 like:

I honestly have no idea how to do something like this. I've only done very basic SQL queries before, like finding all rows where the X equals Y.

SQL isn't really geared to dynamically handling columns.

One approach suggested in the comments is to show nulls for the people that don't share a shift with Jim, using a case expression

SELECT week, date, jim,
       CASE chad WHEN jim THEN chad END,
       CASE ernest WHEN jim THEN ernest END,
       CASE rogier WHEN jim THEN rogier END
FROM   shifts

A slightly nicer (IMHO) solution is to use a case expression to display the name of the person sharing a shift with Jim:

SELECT week, date, jim,
       CASE jim 
            WHEN chad THEN 'Chad'
            WHEN ernest THEN 'Ernest'
            WHEN rogier THEN 'Rogier'
       END
FROM   shifts

But ultimately, both of these are workarounds for a table design that isn't sufficiently normalized.
A more idiomatic approach would be to have a row in the table for each person's shift (i.e., your columns would be week, date, shift and name), and then self-join the table:

SELECT j.week, j.date, j.shift, o.name AS who_is_with_jim
FROM   shifts j
LEFT JOIN shifts o ON j.week = o.week AND
                      j.date = o.date AND
                      j.shift = o.shift AND
                      j.name = 'Jim' AND
                      o.name != 'Jim'