All my my .net purepaths are not showing any of my classes/methods of my application but rather just generic tags like web request, synchronous invocation, asynchronous invocation, sync work SendAsync, etc.
How can I see the call structure/stack of my application?
Those points in the code-level are instrumentation points - places where instrumentation of the code (or errors) happened. Typically instrumentation provided by built-in sensors.
For full stack hierarchy - I believe you want to see the method hotspots view. Either for the selected PurePath or for set of requests.
See the following topic - or just open method hotspots for your currently analyzed context.
If this is not what you are looking for, can you describe your use case?