How to display different timeshift on same graph

Grafana
1

I search many questions and answers. It seems the official documentation of time regions can not tell me how to display different timeshift on same graph. For example, I want to show the metric of online user number with the comparison between today, yestoday and 7 days ago.

time%20region
time%20region836×266 13.9 KB

This is what I see on the grafana edit panel. Why there is only exactly Monday, Tuesday etc? Can I set now-1d or now-7d?

I use:
Grafana v6.1.3
InfluxDB v1.7

2

First, you can write a scrit for today like:
SELECT sum() AS “Today” FROM "" WHERE time >= ‘2020-12-21T00:00:00Z’ GROUP BY time(1m)
Second
SELECT sum() AS “Yesterday” FROM "" WHERE time >= ‘2020-12-20T00:00:00Z’ and time <= ‘2020-12-20T23:59:00Z’ GROUP BY time(1m)
third:
SELECT sum() AS “Last7day” FROM "****" WHERE time >= ‘2020-12-14T00:00:00Z’ and time <= ‘2020-12-14T23:59:00Z’ GROUP BY time(1m)

after you choose concatenate under the transfomation tab