$phone = "{=Document:PHONE}";
$res = Bitrix\Crm\FieldMultiTable::getList([
'filter'=>[
"!=ELEMENT_ID"=>"{=Document:ID}",
'ENTITY_ID'=>'LEAD',
'TYPE_ID'=>'PHONE',
'VALUE'=>$phone
],
'select'=>[
'ELEMENT_ID'
]
]);
$arResIds = [];
while($ob=$res->fetch()){
$arResIds[] = $ob['ELEMENT_ID'];
}
$this->SetVariable('Variable1',$arResIds);