Index View donot show 'Contains' operator for (exposed) filter
I used hook_search_api_views_query_alter from search_api_views.api.php.

function MYMODULE_search_api_views_query_alter(&amp;$view, &amp;$query) {
  // Altering the title filter to operator LIKE which is not available in the 
  // views itself.
  if ($view-&gt;name = '[VIEWNAME]') {
    if (!empty($query-&gt;where[1]['conditions'][0][1])) {
      $query-&gt;where[1]['conditions'][0][1] = '%' . $query-&gt;where[1]['conditions'][0][1] . '%';
      $query-&gt;where[1]['conditions'][0][2] = 'LIKE';
    }
  }
}