Are nested fields no more supported in instrumentation?

[dibericky]

In the latest version of the doc is said:

Note that nested (dotted) field names are also supported.

And there is an example:

#[instrument(fields(http.uri = req.uri(), http.method = req.method()))]
pub fn handle_request<B>(req: http::Request<B>) -> http::Response<B> {
    // ... handle the request ...
}

In the pre-release documentation instead:

The name of the field must be a single valid Rust identifier, nested (dotted) field names are not supported.

Are nested fields so no longer supported? If so, what's the new idiomatic way to have nested structure in span fields via instrumentation?

For instance the example above how shall be written with the next release of the library?