Custom or conditional title in Tooltip for GroupBar Chart.

[rupeshiisc]

here xPercent is dynamic computed field based on datum 2 different foldGroup. Requirement is when hovering over Selected Entities, title should be "Percentage of Selected Entities Events" on the other bar "Percentage of Comparative Events", In below "title" : {} so it display [object, object]: xPercent's value. Is there any way to display dynamic title and value in Tooltip?

"tooltip": [
				{
					"field": "locationName",
					"title": "Location Name"
				},
				{
					"field": "xPercent",
					"format": ".2%",
					"title": {
          "signal": "datum.foldGroup === 'Selected Entities' ? 'Percentage of Selected Entities Events' : 'Percentage of Comparative Events'"
        }
				}