How can I get multiple properties in a visualization using a document from ES index?

I'm trying to create a visualization with a query to Elastic Search, however, I'm having trouble getting the values correctly, I can render a chart only when I aggregate by a count of documents, however, I want to display my values over time, in this case, it's a Vehicle Speed Vs Battery Current.

Any ideas what I might be doing wrong? This is my code so far.

{
  "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
  "title": "Battery Current vs Vehicle Speed",
  "data": {
    "url": {
      "%context%": true,
      "%timefield%": "dateTimeReceived",
      "index": "vehicles",
      "body": {
        "aggs": {
          "time_buckets": {
            "date_histogram": {
              "field": "dateTimeReceived",
              "interval": {"%autointerval%": true},
              "extended_bounds": {
                "min": {"%timefilter%": "min"},
                "max": {"%timefilter%": "max"}
              },
              "min_doc_count": 0
            }
          }
        },
        "size": 1000
      }
    },
    "format": {"property": "hits.hits"}
  },
  
  "repeat": {
    "layer": ["datum._source.propA.propB.vehicleSpeed", "datum._source.propA.propB.batteryCurrent"]
  },
  
  
  
  "spec": {
  "scales": [
    {
      "name": "yscale",
      "type": "linear",
      "zero": true,
      "domain": {
        "data": "aggregations.hits.hits", "field": {"repeat": "layer"}
      },
      "range": "height"
    }
  ],
  "axes": [
    {"scale": "yscale", "orient": "left"}
  ],
    "mark": "line",
    transform: [{
      calculate: "toDate(datum._source.dateTimeReceived)",
      as: "time"
    },
   
    ]
    "encoding": {
      "x": {
        "field": "time", 
        "type": "temporal",
        "timeUnit": "hoursminutes",
        "axis":{ title:"Date"}
        },
      "y": {
        "aggregate": "count",
        "field": {"repeat": "layer"},
        "type": "quantitative",
        "title": false
      },
      "color": {"datum": {"repeat": "layer"}, "type": "nominal"},
     
      "tooltip":[{
        "field": "time_buckets.buckets.key_as_string"
        "type": "temporal"
        "title":"Date"
      },{
        "field": "datum._source.propA.propB.vehicleSpeed"
        "type": "quantitative"
        "title":"Speed"
      },{
        "field": "batteryCurrent"
        "type": "quantitative"
        "title":"Battery Current"
      }]
    }
  }
}

In my encoding -> y -> aggregate I wanted to replace it with something that would give me the value instead of the document count, however when I do it I get the error "Infinite extent for field "datum._source.propA.propB.vehicleSpeed": [Infinity, -Infinity]"