Hello Mr. Ketterer,
I'm not sure what you mean by "System Org Unit". Your image was not attached properly. And which process notation are you using: BPMN or EPC?
In EPC it's simple as that: You connect application system types to process steps with the "supports" connection. Likewise you connect roles to the process steps with the "carries out" connection. Then you use a two-step query following the connection from the role via function to supporting application system types and there you are.
If you are using BPMN it depends on your "flavour" of BPMN. If you are using Enterprise BPMN model types you might have the tasks in a role lane, in which case you only have to add the application system types in function allocation diagrams or use content type modelling to add the supporting applications in the properties. In BPMN there is no standard conformant way to show it in the model. But you may add this information just the same as you would in EPC. Just it does not look like pure BPMN anymore. The BPMN standard was not made for this use-case. You would have to add the application system type and "supports" connection to your method filter.
Regards, M. Zschuckelt