CouchGrid only allows "shallow keys"

When using CouchGrid, It is only possible to query parameters in the first level. A way of making deeper keys would be greatly appreciated.

I have tried to hack the code to do it, but I really need more insight and some guidance before being able to do it right.

Further explanation:
If I have an item database for a transnational greengrocer chain

{
  "name" : "cucumber",
  "barcode" : "1234567890123",
  "danish_details" : {
    'local_price' : 7.00,
    'local_name' : 'agurk',
  },
  "swedish_details" : {
    'local_price' : 9.00,
    'local_name' : 'gurka',
  },
  "norwegian_details" : {
    'local_price' : 22.00,
    'local_name' : 'agurk',
  }
}

I am the danish local manager, and want to make use a CouchGrid for my point-of-sale software, and it needs these keys:
The danish name of the item, the danish price and the international barcode. To this, I would intuitively make my keys like this:

keys=['danish_details.local_name','danish_details.local_price','barcode']