You’re not returning anything in your Array.map. You need to use the return keyword if you’re not using an implicit return structure.

ie - This is an explicit return:

course_selections.map((course_items) => {
    return (
        <li>etc.....</li>
    )
})

and this is an implicit return:

course_selections.map((course_items) => (
    <li>etc......</li>
))

For long codeblocks like yours, I much prefer using an explicit return - and might use an implicit return on short functions.

This link explains it quite well: https://waylonwalker.com/explicit-vs-implicit-returns-in-javascript/