5G system and beyond targets a gigantic number of emerging applications and services that will create an extra overhead on the network traffic. Moreover, these industrial verticals have aggressive, contentious, and conflicting requirements that make the network have an arduous mission for achieving the desired objectives. It is expected to get requirements with close to zero time latency, high data rate, and network reliability. Fortunately, a ray of hope comes shining the way of telecom providers with the new progress and achievements in machine learning, cloud computing, micro-services, and the ETSI Zerotouch network and Service Management (ZSM) era. For this reason there is a colossal impetus from industries and academia towards applying these techniques by creating a new concept called Cognitive Cloud Native environment that can cohabit and adapt according to the network and resource state, and perceived Key Performance Indicators (KPIs). In this paper, we pursue the aforementioned concept by providing a unified hierarchical closed-loop network and service management framework that can meet the desired objectives. Also, we have proposed a cloud-native simulator that accurately mimics cloud-native environments, and enables us to quickly evaluate new frameworks and ideas. The simulation results demonstrate the efficiency of our simulator for parroting the real testbeds in various metrics.