If application from your definition isn't anything that have web interface, answear is you can't. Applications are created for monitoring of user expirience on frontend level. If you don't have interface in web or mobile app, you cannot use them (windows form and simmular apps also can't be monitored that way).
Such applications are monitored only as processes and services. In dynadatrace meaning of Application has been redefined from Appmon time 🙂
If this is the case, then my question isn't completely answered. In this scenario, how do I group together processes and services in order to create an application? For example, we have many Java applications that don't have a front end web portal; instead, some of them have MQ messaging front ends!
@William S. case you are talking about is good place for creating management zones 🙂 and tagging maybe. When you will create management zone you will have special filter on top which will be filtering entities from particular application (in your definition).
Another thing is creating automatic tag rules that will help you identify particular apps when you are looking at environment globally. Tags are also cool when you want create custom chart from only one app because they can also be used as filters 🙂
It's also important to prepare proper proces group detection, process group naming, host naming and services naming to make environment easier to read.