AT:

• there is a new groupBy option :

  groupBy: {
    type: 'duration',
    value: null
  }
  

• this groupBy can be used with the ProcessInstance Count view
• the duration to group on by is the process instance duration
  • the duration for running instances is calculated up to the current point in time
• the bucket interval is calculated dynamically (like groupByDate/groupByVariable Automatic),
• the API docs are extended by this new groupBy option

Out of scope:
Combined report range handling (calculate buckets for combined report) is out of scope and will be addressed with OPT-4103