How to make a variable dependent on another or change datasource based on variable choice

Datasource: CloudWatch
Version: 5.4.2

I have an issue where i have to display a dashboard for a certain group of AWS ec2 instances.
I get the list of instances using a variable that gets populated from a tag on the instances.

ec2_instance_attribute($region, Tags.Name, {“tag:TagKey”: [“Some Tag Value”]})

I want to reuse the same dashboard to allow users to show different groups of instances.
I need to change the tag value in the variable based on a dropdown, which is OK, but the instances are in different AWS accounts which then requires the users to switch Grafana datasources by changing a second dropdown. This also reuires the users to know which group is in which account (which they do not).
This also presents an issue because you can only change one dropdown at a time and as soon as you change one, the list of instances becomes empty and the graphs display errors, until you pick the correct datasource.

Is there any way to make dropdown variable choices dependent on one another?
Or make dropdown choices have a DisplayName/Value instead of just a value?

you can use Datasource type variables.

Thanks for the suggestion Daniel, but how can you make the Datasource variable change when another variable changes? That is what I’m trying to do.