Kibana Vega - How to display multiple results in a date histogram

I am wonder if it is possible to display more than one aggregated result in a date histogram?

My Vega query is

{
  $schema: https://vega.github.io/schema/vega-lite/v2.json
  title: Daily Count

  data: {
    url: {
      %context%: true
      %timefield%: @timestamp
      index: my_index
      body: {
        size: 0      
        aggs: {
          time_buckets: {
            date_histogram: {
              field: @timestamp
              calendar_interval: day
              min_doc_count: 0
            }
            aggs: {
              a_call_sum: {
                sum: {
                  field: a_call
                }
              }
              e_call_sum: {
                sum: {
                  field: e_call
                }
              }
            }
          }
        }
      }
    }
    format: {property: "aggregations.time_buckets.buckets"}
  }
  
  mark: bar
  
  encoding: {
    x: {
      field: key
      type: temporal
      axis: {title: false}
    }
    y: {
      field: a_call_sum.value
      type: quantitative
      axis: {title: "Call count"}
    }
  }
}

I was wondering if it is possible to display both a_call_sum and e_call_sum in the same visual side by side in their respective bin/interval or maybe I am using the wrong visual type?

Hi @Amphagory!

This Discuss post looks similar to your request.

Have you looked into using flatten transform? Another option might be to use composite aggregation.