The SAP Hana Enterprise Cloud (HEC) is a fully managed subscription based cloud service. The "general" operation of the system is done by the HEC team and there is no need for you to take care of it. But as it is a private cloud and many customer use it as extension of their existing on premise solution there might be the need to integrate the systems located in HEC into existing application lifecycle management processes (e.g. ChaRM) or Run SAP Like a Factory scenarios (e.g. Interface Monitoring, System Monitoring, Business Process Monitoring). In order to achieve this kind of integration your systems located in HEC need to be connected to your on premise SAP Solution Manager. Once the connection is established the setup of the processes/scenarios is straight forward like for any of your on premise systems.
You want to connect your SAP HANA Enterprise Cloud (HEC) system to your on premise SAP Solution Manager. As you need to be aware, that HEC is using SAP Focused Run for their Operations, you will have a coexistence of SAP Solution Manager and SAP Focused Run by default. For further information, check the considerations for SAP Focused Run and SAP Solution Manager.