The Kubernetes clusters and Kubernetes namespaces cost views are now generally available in Cost analysis within Azure portal. You can view the aggregated costs for all your AKS clusters and namespaces across a subscription and drill down into infrastructure and namespaces costs of a cluster. Having granular visibility will help you gain deeper insights into your infrastructure costs enabling you to allocate and optimize your AKS costs efficiently.
Please refer to the articles below for instructions on installing the add-on and accessing the cost views.