There are multiple ways to do that, I'd probably use instance in action name:
1) configure 2 actions on the agent: StartA, StartB
2) Create 2 DCIs - Process.Count(A) and Process.Count(B) with threshold "< 1" on both (or any other way how you detect that process is down), set instance to "A" and "B" respectively (in thresholds tab, will be used in action name) and some activation event (can be the same).
3) handle this event in EPP with "Execute command on remote node via agent" action, as agent action name put something "Start%<instance>"
1) configure 2 actions on the agent: StartA, StartB
2) Create 2 DCIs - Process.Count(A) and Process.Count(B) with threshold "< 1" on both (or any other way how you detect that process is down), set instance to "A" and "B" respectively (in thresholds tab, will be used in action name) and some activation event (can be the same).
3) handle this event in EPP with "Execute command on remote node via agent" action, as agent action name put something "Start%<instance>"