Getting group product when i try filter product by url_key

I have a Simple product

And a group product with that simple product

Now, when I do next query

{
  products(filter: { url_key: { eq: "test-product-1" } }) {
    items {
      name
      sku
      url_key
      stock_status
      price_range {
        minimum_price {
          regular_price {
            value
            currency
          }
        }
      }
    }
    total_count
    page_info {
      page_size
    }
  }
}

I get two products, but I want get only simple product because I write it url_key.

{
  "data": {
    "products": {
      "total_count": 2,
      "items": [
        {
          "name": "Test group product",
          "sku": "tgp1",
          "url_key": "test-group-product",
          "price_range": {
            "minimum_price": {
              "regular_price": {
                "value": 99,
                "currency": "USD"
              }
            }
          }
        },
        {
          "name": "Test simple product 1",
          "sku": "tsp1",
          "url_key": "test-simple-product-1",
          "price_range": {
            "minimum_price": {
              "regular_price": {
                "value": 99,
                "currency": "USD"
              }
            }
          }
        }
      ],
      "page_info": {
        "page_size": 4,
        "current_page": 1
      }
    }

Please, say me. What I need to do to get only simple product when I write it url_key?

Maybe someone know why it works so?