How can I overlay multiple fields in Dashboard Studio Column Chart?

[_smp_]

I have a saved report with three output fields that I want to add to a Column chart in Dashboard studio. Two of the three fields contain static values (license limit and optimal utilization threshold) that I want to add as overlays to the third utilized SVC field. I can't seem to get the JSON correct. This is as close as I have come. How can I add two fields as overlays in a Column chart? Image attached.

{

    "type": "splunk.column",
    "dataSources": {
        "primary": "ds_search_1"
    },
    "title": "SVC License Usage (today)",
    "options": {
        "yAxisAbbreviation": "off",
        "y2AxisAbbreviation": "off",
        "showRoundedY2AxisLabels": false,
        "legendTruncation": "ellipsisMiddle",
        "showY2MajorGridLines": true,
        "xAxisTitleVisibility": "hide",
        "yAxisTitleText": "SVC Usage",
        "overlayFields": ["optimal utilization threshold", "license limit"],
        "columnGrouping": "overlay"
    },
    "context": {},
    "showProgressBar": false,
    "showLastUpdated": false
}

[ITWhisperer]

Try without 

"columnGrouping": "overlay"

[_smp_]

That was one of many things I've tried. Removing that property results in a timechart with a separate column for each field.

[nickdekkersmt]

did you found a solution?