Product instead of sum for scoring bool query

Hello!

I am trying to score bool query using product instead of sum. I started
with custom_score query:

{
"query" : {
"custom_score" : {
"query" : {
"bool" : {
"must" : [
,

]
},
"script": ?
}
}
}
}

  • but then I found no way to refer to scores of and
    inside the script.

How do I calculate score of bool query using product of it's subqueries?