How to get dashboard analytics by sub domain

hi all.

i’m try Cloudflare api in zones/:zone_identifier/analytics/dashboard its show help full data.
and how to get data like zones/:zone_identifier/analytics/dashboard but only show data analytics for sub domain.

i’m already try zones/:identifier/dns_analytics/report/bytime and not showing data record, just show this:

    "result": {
        "rows": 0,
        "data": null,
        "data_lag": 60,
        "min": {},
        "max": {},
        "totals": {
            "queryCount": 0
        "query": {
            "dimensions": [],
            "metrics": [
            "filters": "",
            "since": "2018-09-03T12:20:00Z",
            "until": "2018-09-03T14:20:00Z",
            "time_delta": "minute",
            "limit": 1000
    "success": true,
    "errors": [],
    "messages": []

@KentonVarda or @zack can you help me.