How to implement sampling?

Question

Laravel

There is a Posts table.
There are Comments to Posts.
Posts: id: 1, title: "Hello, World!"
Comments: [ {id: 1, body: "lorem ipsum dolor."}, {id: 33, body: "lorem dolor text."} ]
When a request is made to Laravel, it looks like this:
GET /posts/hello- world/2 - This request should return a comment with id 33.
I looked in the documentation, it seems there is a filter , but I'm not sure if this is what I need.
Can you please tell me how can I implement this correctly?