We have several instances of a process model where process security is assigned

I wasn't able to find any out of the box functions or plugins that would accomplish this. You would likely need to create a custom function plugin to get process security for running instances.

Also, keep in mind that in a single process instance, there might be multiple flows, each of which could have its own security model. This could be a pitfall for any sort of intuitive organization.

Thank you for the reply. Could you point me to the API that gets the process instance security?

forum.appian.com/.../
Take a look at the Security class, and the getNative() method