How can I assign ec2 instance name to legend when using grafana and aws cloudwatch?

grafana v9.1.8 (3c0c14de5d) / Linux/UNIX

After getting EC2 CPU utilization per instance using grafana and aws cloudwatch, I want to display the legend in the middle like ec2-instance-name(i-0…), but I can’t find a variable other than ${}. When using ${__series}, return [Object object], so I think I can get the instance name. Is there a way?