I´m using a USER (relational) field to choose specific users (like editors..) on a dropdown menu.
How to show it on frontend?
I can populate USERNAME (mine in case) but not USER field.
To get an ACF field associated with the user you need to provide the user id in the form of "user_{$user_id}" or the user object as returned by wp_get_current_user()
$user_id = get_current_user_id();
$value = get_field('field_name', 'user_'.$user_id);
// OR
$user = wp_get_current_user();
$value = get_field('field_name', $user);
The above would be for the current user, for other users you’d supply the correct user ID
https://www.advancedcustomfields.com/resources/how-to-get-values-from-a-user/
