WordPress meta key search-Collection of common programming errors

I have some problems with wordpress meta key relations and search parametrs. I can not get this to work:

?meta_value=Dažadi&id=32&cp_city=Cesis

Search results is only filtering by meta_value, not of cp_city and meta_value.

cp_city is also meta key value.

But this call is working and filtering:

?meta_value=Pardod&id=32

I need to filter by two or three parametrs.

Here is functions code to filter.