Inverse of `fieldprefix` function

There is fieldprefix function, which transform flat structure into nested objects. Is it possible in some way to have an opposite operation?

As an example, consider following article structure written in json:
Input:

json_str = """
{
  "author": {
      "name": "XXX"
      "link": "https://example.com"
  },
  "title": "YYY",
  "body": "ZZZ"
}
"""

What I want is to put it in flat structure (because in my particular case I do not need author as a separate object)

struct Article
   author_name::String
   author_link::String
   title::String
   body::String
end

And to be able to read articles with the construct like

JSON3.read(json_str, Article)

Start by tracing the existing fieldprefix function and how JSON3.read(json_str, Article) handles nested fields. Define the inverse mapping needed for author.name and author.link to populate author_name and author_link, with successful deserialization into the shown Article structure as the completion criterion.