Calculate sum of duration for Sub calls

[rajkskumar]

I have data in the following structure received for every event. Some events have just one or two sub calls and some have more sub calls. I need to calculate the sum of the total duration.

subCalls: [ [-]
         { [-]
           completionTimeMs: 69
           method: GET
           statusCode: 200
         }
         { [-]
           completionTimeMs: 77
           method: GET
           statusCode: 200
         }
         { [-]
           completionTimeMs: 956
           method: POST
           statusCode: 200
         }
         { [-]
           completionTimeMs: 201
           method: PATCH
           statusCode: 204
         }
       ]

The below search calculates the sum of all the values in all the events instead of every event. Please suggest on how to proceed further.

mysearch
| eventstats sum(processRelevantFields.eventDetails.subCalls{}.completionTimeMs) as totalDuration
| table traceId, totalDuration