How implement nested array result with its populated detailed info in Loopback 4 and mongoDB

Question

I wanted to store categories and its products Ids as an array in the collection. On get method I need show category info as well as product details as mentioned below .Is there any best with relational model in loopback? I am new in Loopback and node js, please suggest best practice.

Category
{
    "id": "1",
    "Category": "Category 1",
    "products": [
      "1",
      "2"
    ]
},
{
    "id": "2",
    "Category": "Category 2",
    "products": [
      "2",
      "3"
    ]
}

Products
{
    "id": "1",
    "title": "Product 1"
},
{
    "id": "2",
    "title": "Product 2"
},
{
    "id": "3",
    "title": "Product 3"
}

Result 
{
    "Category": "Category 1",
    "products": [
        {
       "id": "1",
           "title": "Product 1"
    },
    {
       "id": "2",
           "title": "Product 2"
    }
    ]
},
{
    "Category": "Category 2",
    "products": [
        {
       "id": "2",
           "title": "Product 2"
    },
    {
       "id": "3",
           "title": "Product 5"
    }
    ]
}