Istio Multi Cluster Security Management

Hi, Istio supports authorization policies and authentication policies for a single-cluster and multi-cluster federation. In a use-case, where there are 2 different Istio service meshes that need to expose services securely with the help of an ingress gateway. How can we ensure that the 2 meshes understand the authorization policies across the gateway.

There are different types of multi-cluster installations on Istio / Install Multicluster. Which type is used in your installation?
There is a trouble-shooting guide for multicluster: Istio / Troubleshooting Multicluster.

I am trying to have 2 different service mesh on different clusters.