julienmonnerie/site/controllers/exhibitions.php

<?php

return function ($site, $page) {

    // Get home page object
    $homePage = $site->homePage();

    // Get exhibitions field content (stored as yaml) and parse it to return an array
    $exhibitions = $page->exhibitions()->yaml();

    // Add url based title to each exhibition
    foreach ($exhibitions as &$exhibition) {
        $exhibition['title'] = str_replace(['http://', 'https://', 'www.'], '', $exhibition['url']);
    }

    // Get contact fields content
    $email = $page->email();
    $instagram = $page->instagram();

    return [
        'homePage' => $homePage,
        'exhibitions' => $exhibitions,
        'email' => $email,
        'instagram' => $instagram
    ];
};