Add a variable for an AWS related dashboard

I am using the AWS Application ELB dashboard.
However, I need to add some additional panels, specifically the Healthy/Unhealthy hosts count.
The Dashboard doesn’t have TargetGroup so, I need to add those variables.

I created a new variable with the name targetgroup as:
Name: targetgroup
Type: Query
Label: TargetGroup
Data Source; AWS
Query: dimension_values($region,AWS/ApplicationELB,LoadBalancer,TargetGroup)
Multi Value: Yes

However, the variable is empty. The relevant drop down menu is blank and it’s not updated.
Any help would be appreciated.

Let me answer my own question:
The correct query is:


Does this work?
As you can’t get HealtyHostCount without specifying TargetGroup AND LoadBalancer.