Add an ACF value to a CPT list column

gistfile1.php

/**
 * Add a "Author" column to theses CPT
 */
function add_theseauthor_columns($columns) {
    $columns['theseAuthor'] = 'Author';
    return $columns;
}
add_filter('manage_theses_posts_columns' , 'add_theseauthor_columns');

/**
 * Get the ACF fields and display them in "theseAuthor" column
 */
function custom_columns( $column, $post_id ) {
    if ( $column == 'theseAuthor') {
        echo get_field('lastname', $post_id) . " " . get_field('firstname', $post_id);
    }
}
add_action( 'manage_posts_custom_column' , 'custom_columns', 10, 2 );