[WhaLberg]

Add a plugin to global_start template including these codes:

PHP Code:

if (strpos($_SERVER['HTTP_REFERER'], 'www.x.') != false)
{
$show['truereferrer'] = true;
}
else
{
$show['truereferrer'] = false;
} 


In navbar use

<if condition="$show['truereferrer']">your codes</if>

By the way, I didn't test the php code but it should work. If you face any error, let me know.