Mixer, pilot , citadel communication

Dear All,
According to all Istio Architectures [1,2] there is no communication possible between Mixer and pilot and other Istio components. I am wondering if there is a way to communicate between Mixer and pilot and citadel? and if there is how?
I appreciate any comment on this.
[1]. https://istio.io/docs/concepts/what-is-istio/arch.svg
[2]. https://itnext.io/istio-service-mesh-the-step-by-step-guide-adf6da18bb9a

Best regards

@soheilade can you elaborate on what you are trying to achieve and why you would want Mixer to be communicating directly with Citadel, etc.?