[json] Unmarshaling nested JSON objects

There are a few questions on the topic but none of them seem to cover my case, thus I'm creating a new one.

I have JSON like the following:

{"foo":{ "bar": "1", "baz": "2" }, "more": "text"}

Is there a way to unmarshal the nested bar property and assign it directly to a struct property without creating a nested struct?

The solution I'm adopting right now is the following:

type Foo struct {
    More String `json:"more"`
    Foo  struct {
        Bar string `json:"bar"`
        Baz string `json:"baz"`
    } `json:"foo"`
    //  FooBar  string `json:"foo.bar"`
}

This is a simplified version, please ignore the verbosity. As you can see, I'd like to be able to parse and assign the value to

//  FooBar  string `json:"foo.bar"`

I've seen people using a map, but that's not my case. I basically don't care about the content of foo (which is a large object), except for a few specific elements.

What is the correct approach in this case? I'm not looking for weird hacks, thus if this is the way to go, I'm fine with that.