WordPress Post List (Admin)

wp-post-list.php

<?php

/*
 * Manage Vacancies Columns
 */
add_filter( 'manage_vacancies_posts_columns', function ( $columns ) {

    // Checkbox column
    $cb = $columns['cb'];

    // Change Title row name
    return array(
        'cb'            => $cb,
        'groups'        => 'Groups'
    );

} );

/**
 * Get data for custom vacancies columns
 */
add_action( 'manage_vacancies_posts_custom_column', function( $column, $post_id ) {

    // Get the fields
    $fields = get_fields($post_id);

    if ( $column === 'groups' ) {
        // Echo things here
    }

}, 10, 2 );