IBLOCK_POSTS,
"ACTIVE"=>"Y",
"!PROPERTY_SIMILAR_PREVIEW"=>false
);
$arSelect = Array (
"ID", "NAME", "PROPERTY_SIMILAR_PREVIEW"
);
$res = CIBlockElement::GetList(Array("ID"=>"ASC"), $arFilter, $arSelect);
while($row = $res->GetNext()):
$file = CFile::GetPath($row['PROPERTY_SIMILAR_PREVIEW_VALUE']);
?>