Using a field from influxdb as the title / label for a point on a grafana dashboard

As the title suggests, I have a Grafana 'graph' that I populate with points from InfluxDB. The elements of the time series have two fields: 'rate' and 'source'. The graph is time on the x-axis of course, and 'rate' on the y-axis. I'd like to see 'source' when I hover over a point. Is this possible with Grafana / Infux?`