I know that this is an old post, but I managed to do the variable thresholds using new alerting and InfluxDB. next step for me will be using data manipulation plugin to have an Input for each Individual threshold on the same dashboard that monitors the alerts, so the user can tweak the threshold if needed.
The trick was to have the same “schema” on both sources, since right now I don’t have the values on a database I used array.form() to create a table based on an array, but as long as I can manipulate the data to have the same schema (basically pivot() and group() functions using Influx DB), I believe it is possible using any other data source.
Same here, I found Node-red very useful to do all the logic stuff that is not possible to do either on Grafana or InfluxDB.