Выводит инфоблоки в админке только текущего сайта (https://dev.1c-bitrix.ru/community/webdev/user/11948/blog/2692/)

init.php

<?
AddEventHandler('main', 'OnBuildGlobalMenu', 'ASDOnBuildGlobalMenu');
function ASDOnBuildGlobalMenu(&$aGlobalMenu, &$aModuleMenu)
{
   $arSites = array(
            'www.site.ru' => 's1',
            'site.ru' => 's1',
            );

   $arIBsites = array();
   $rsIB = $GLOBALS['DB']->Query("SELECT * FROM b_iblock_site;");
   while ($arIB = $rsIB->Fetch())
      $arIBsites[$arIB['IBLOCK_ID']] = $arIB['SITE_ID'];

   foreach ($aModuleMenu as $k => &$v)
   {
      if($v['parent_menu']=='global_menu_content' && $v['module_id']=='iblock' && $v['page_icon']!='iblock_page_icon_settings')
      {
         $cUnsets = 0;
         $cAll = count($v['items']);
         foreach ($v['items'] as $kk => $vv)
         {
            $BID = array_pop(explode('/', $vv['items_id']));
            if ($arIBsites[$BID] != $arSites[$_SERVER['SERVER_NAME']])
            {
               unset($v['items'][$kk]);
               $cUnsets++;
            }
         }
         if ($cUnsets == $cAll)
            unset($aModuleMenu[$k]);
      }
   }
}
?>