Divide in grafana alert


Using Grafana 6.1.4, the interface is quite different from many examples I see on the internet. And it’s driving me nuts.

I try to set up alerting. Since my numbers as well as my relative numbers are not fixed I need percentiles. And I cannot figure out how to do this. I read about DivideSeries and cannot find anywhere where I can use this.

OK setup: Grafana 6.1.4 with Elastic Search 6.7 back-end.
I took a a Singelstat (just like told me here: https://danlimerick.wordpress.com/2017/01/29/graphite-and-grafana-how-to-calculate-percentage-of-totalpercent-distribution/ ) and created 2 queries of which the one needs to be calculated unto a percentile of the other. Singlestat shows that number (somewhere between 100 and 0) and fires when exceeds the treshold I set.

Sounds so easy, Yet I cannot find it.
Anyone knows help?