in this post, I'll show you how to make theme suggestions for pagers in drupal 8.
<?php
/**
* @param array $suggestions
* @param array $variables
* @param $hook
*/
function mymodule_theme_suggestions_pager_alter(array &$suggestions, array $variables, $hook)
{
$var = \Drupal::routeMatch()->getParameter('entity');
if (isset($var) && !empty($var->getEntityTypeId()) && $var->getEntityTypeId() == "search_page") {
$suggestions[] = $hook . '__search__page';
}
}
