How to create a feature burndown chart in Azure DevOps

Question

The Azure DevOps documentation that describes Burndown and Burnup Charts describes the following types of burndown charts (quotations are from the link above):

1. "A sprint burndown tracks the sprint backlog completion by end of the sprint"
2. "A release burndown tracks the release backlog completion by the end of the release" 
3. "A bug burndown chart to track the completion of a set of bugs by a certain date" 

However, I would like to implement a feature burndown where the X-axis is a sprint or date (same as either of the 2 charts above) and the y-axis is either the count of the number of stories + bugs or the sum of the points. Most importantly, this feature burndown chart would show only the children of a specific feature item, such as this list of 4:

How can I please generate this feature burndown chart described above?