在嵌套数组中过滤数组的最佳方法

Question

我需要找到一种更好的方法来实现从更大的数组中提取数组并将该子数组过滤到一个新的子数组中，我想避免将 for 循环用于另一个 for 循环，我认为这可以用数组来完成map 或过滤器，但不知道如何异步使用它，这是我的代码：

/* This is how to response looks like */
const example_response = [
    {
        "customer_id": 77495325,
        "line_items": [
            {
                "external_inventory_policy": "decrement_obeying_policy",
                "grams": 0,
                "price": "49.00",
                "product_title": "Coffret Planète Noël Édition limitée",
                "properties": [],
                "quantity": 1,
                "shopify_product_id": 6646207021135,
                "shopify_variant_id": 39696573923407,
                "sku": "109P72AN23",
                "subscription_id": 203337080,
                "tax_lines": [
                    {
                        "price": "8.17",
                        "rate": "0.2",
                        "title": "FR TVA"
                    }
                ],
                "title": "Cvdvsdvde",
                "variant_title": ""
            }
        ],
        "note": "",
        "note_attributes": [],
        "processed_at": "2021-12-13T16:03:01",
        "scheduled_at": "2021-12-13T00:00:00",
        "type": "CHECKOUT",
        "updated_at": "2021-12-13T16:03:01"
    }
];
 
async function getOrdersList() {
  try {
    let url = `MY_URL`;
    
    let data = await fetch(url);
    let res =  await data.json();
    if(!res) throw new Error({'error':'no response'});
    
    let orders = res.orders;
    let lineItems = [];
    let lineItem = {};
    
    for (const [i, value] of orders.entries()) {
        let inlineItems = value.line_items;
        for (const [j, value2] of inlineItems.entries()) {
            lineItem['id'] = value2.shopify_product_id;
          lineItem['qty'] = value2.quantity;
          lineItems.push(lineItem)
        }
    }
    
    return lineItems;
  }
  catch(error) {
        console.error(error);
      } 
}

/* Output */
[{"id":6646207021135,"qty":2}]