When we have a concern for the securing of analytic views can be achieved by few number of ways
Firstly, we can do that by securing their parent package. It allow us to limit developers from modifying the packages that they do not own.
Nextly, we do ensure the security of them them within the _SYS_BIC schema all the way down to the individual components of the model.
If we consider the following example, under database case, we can limit one Database role to only see from 1 of 15 Analytic Views available within the HANA repository and lastly we can apply the required Analytic Privileges to secure data rows for query execution when its returning.
Also we can create filters in the Universe or Reports when accessing an Analytic View particularly via a Universe. and they are passed to SAP HANA for processing We can also create Universes directly on the SAP HANA tables and by pass SAP HANA modeling content . But in this method filters are executed directly against the SAP HANA tables.
Also i just want to input that we can have multiple fact tables in the analytic view but remember that it will slowdown the performance.
My suggestion is always It is good to combine them into a single table, utilizing Data Services 4.0 before loading them into SAP HANA.