How to pass the label name in the title of the line graph in Splunk dashboard studio?

[super_edition]

Hello 

I have dropdown element in my dashboard with 3 options as mentioned below.

{
    "options": {
        "items": [
            {
                "label": "Both",
                "value": "*"
            },
            {
                "label": "dublin",
                "value": "*DDUUBBLLIN*"
            },
            {
                "label": "singapore",
                "value": "SSIINNGG"
            }
        ],
        "defaultValue": "*",
        "token": "datacenter"
    },
    "title": "data-center",
    "type": "input.dropdown"
}

I want to pass the label name in the title of the line graph:

If I use token-name with dollar sign like this: $datacenter$ it displays selected label's value:

transaction per hour at DDUUBBLLIN datacenter - when the user selects Dublin

However I want to display the label name:

transaction per hour at Dublin datacenter - when the user selects Dublin

transaction per hour at Singapore datacenter - when the user selects Singapore

transaction per hour at both datacenter - when the user selects Both