How to use Solr to search for parent documents from child-documents, while displaying the corresponding child-document's score?

Question

I'm conducting a nested document search with Solr, obtaining the corresponding parent documents based on the vector distance of the child documents. So far so good. However, I want to display the vector distance score of the corresponding child-document in the [child] field of the parent documents, but all child-documents are showing a score of 0.

I've spent several days searching resources including the Solr Reference Guide, but I still haven't found the answer I need. Here is an example of the nested document in my Solr:

{
 id: 1,
 doc_type: "parent",
 text: "sentence A. sentence B. sentence C."
 children{[
  {id: 2,doc_type: "child",text_piece: "sentence A.", embedding:[0.1,0.2,0.3...]},
  {id: 3,doc_type: "child",text_piece: "sentence B.", embedding:[...]},
  {id: 4,doc_type: "child",text_piece: "sentence C.", embedding:[...]}
]},
{
 id: 5,
 doc_type: "parent",
 text: "sentence D. sentence E. "
 children{[
  {id: 6,doc_type: "child",text_piece: "sentence D.", embedding:[...]},
  {id: 7,doc_type: "child",text_piece: "sentence E.", embedding:[...]},
]}
}

My query roughly looks like this: q={!parent which='doc_type:parent' score=max}{!knn f=embedding topK=2}[0.2,0.1,-0.5,...]&fl=['*','score','[child]',[explain style=nl]'] translated from pysolr code, please ignore syntax errors if there is any

The results are as follows:

docs: [
{
 id: 1, 
 doc_type: "parent",
 text:"sentence A. sentence B. sentence C. ",
 split_text:[
 {id:2,text_piece:"sentence A.", score:0.0, embedding:[...], [explain]: {'match': False, 'value': 0.0, 'description': 'Not a match'}},
 {id:3,text_piece:"sentence B.", score:0.0, embedding:[...], [explain]: {'match': False, 'value': 0.0, 'description': 'Not a match'}},
 {id:4,text_piece:"sentence C.", score:0.0, embedding:[...], [explain]: {'match': False, 'value': 0.0, 'description': 'Not a match'}}]
 [explain]: {'match': True, 'value': 0.849, 'description': 'Score based on 2 child docs in range from  129 to 130, using score mode Max', 'details': [{'match': True, 'value': 0.849,'description': 'within top 2'}]}
]
'Score based on 2 child docs in range from 129 to 130, using score mode Max'

The results above are just an example. Suppose the score of the sub-document with id=2 is 0.849, and the score of the sub-document with id=3 is 0.5, I hope these two scores can be displayed in their respective score fields.

Currently, I perform a two-step searche on the child-documents and parent documents, and then merge the results. Although I can get the results I need through this compromise method, it is accompanied by a decrease in performance and code readability. If you have a better method, please let me know. Thank you.