How to process partially json structure in go?

Question

JSON

Good day to all!
There is a task to parse json file. Problems in parsing There is no whole file, but there is a problem in parsing part of the file! View file:
-Head category
+ subcategory...
++subcategory parameters and more nested categories...
So, there are 15 head categories in the file, but at the moment I need only 10! How should I best handle the source file: create an array/map/whatever?
At the moment, to parse the entire file, the mem has the construction:

var str1 Menu

  err = json.Unmarshal(bs,&str1)
  if err!= nil{
    fmt.Println("Unmarshal error = ", err.Error())
  }

the Menu structure is quite complex (for me at least!!!):

type Menu struct {
  Catalog []struct {
    MainCategoryName string `json:"mainCategoryName"`
    MainCategorySlice []struct {
      CurrentCategoryName string `json:"currentCategoryName"`
      CurrentCategorySlice []struct {
        EndCategoryName string `json:"currentCategoryName"`
      } `json:"currentCategorySlice"`
    } `json:"mainCategorySlice"`
  } `json:"catalog"`
}

therefore, the problem arises (
How can I best process the incoming file if I later need to take ranges of head categories / a specific head category on request? Should I create an array with elements of the "head catalog" type? or are there some other processing mechanisms, just I don't know about them?
I apologize in advance if my question seems idiotic to someone! I'm just learning to program on my own and on specific tasks, so the questions are like this)

Answer 1

If you don't need to parse all fields - use "-" tag for unnecessary fields.
If you need to parse the structure flexibly - use RAW parsing (standard library functionality)