[source, ruby]
----
response = client.search(
  index: 'products',
  body: {
    aggregations: {
      genres_and_products: {
        multi_terms: {
          terms: [
            {
              field: 'genre'
            },
            {
              field: 'product',
              missing: 'Product Z'
            }
          ]
        }
      }
    }
  }
)
puts response
----
