Using result of Aggregations in calculation

I want to use the results from previous aggregations in another calculation-based aggregation.

Is there a way of doing this currently? E.g via script access, etc

"aggregations": {
"product": {
"aggregations": {
"sales": {
"sum": {
"field": "attempts"
}
},
"onhand": {
"sum": {
"field": "successful"
}
},

        "*overall_success_rate*" : {
           "successful/attempts * 100"   ---- using prev aggregated results 
        }
     }
  }

}