NMCap and NMAPI cannot capture the process information in live capture scenarios.
However, if you have a capture file which was captured using the Network Monitor UI, then you can still read that information from the capture file using our API.
You'll want to make sure you turn Conversations on with NmConfigConversation. And then you can use NmAddProperty and NmGetPropertyValueById, or NmGetPropertyValueByName to retrieve the following properties:
Hope that helps. Let me know if you have any other questions.