You could create a custom group for each environment and add the vCenter Servers and other adapter instances for each environment to a custom group. The custom group's summary will show the alerts for that environment and you could also use the alerts widget on a custom dashboard to filter on the custom group.
I don't think you can use collectors or collector groups for this because I don't see a direct relationship between the collector and all the objects being collected. Clusters, hosts and VMs for example are descendants of vCenter Servers. If you're using other adpaters like the vSAN or storage adapter you can also add those adapter instances to the custom group for their environment.