Drupal 8 preprocess views_view_unformatted__themename

I am trying to access the field content for a view. I have been using dump, kint with varying degrees of success. I have to quit the browser each time I try something new and clear the cache. (I have correctly setup debugging in my settings etc files.
I am coming from a very strong procedural drupal background. I have studies OOP, Symfony but I am just not connecting the dots.
I have function themename_preprocess_views_view_unformatted(&$variables) {
$variables[??????????????]
}
How do I get the value for the fields? any help or pointing me in a direction would be appreciated.