Filter with aggregate value in Query DSL

I think you are looking to add a bucket selector aggregation.

Something similar to the below.

{
  "bucket_selector": {
    "buckets_path": {
      "my_var1": "cpu_per_day",                     
      "my_var2": "max_daily_cpu"
    },
    "script": "params.my_var1 > (params.my_var2 * .6)"
  }
}