How to access placeholder sub-element

[mrw]

HI All, I'm using a custom webhook in my DT environment. What I'd like to do is get the description of an alert included in my alert payload. 

There is no description placeholder, but this can be taken from the ProblemDetailsJSONv2 placeholder. 

{
    "State":"{State}",
    "PID":"{PID}",
    "ProblemID":"{ProblemID}",
    "ProblemImpact":"{ProblemImpact}",
    "ProblemTitle":"{ProblemTitle}",
    "ImpactedEntity":"{ImpactedEntity}",
    "ProblemSeverity":"{ProblemSeverity}",
    "Tags":"{Tags}",
    "ProblemDetailsJSONv2":"{ProblemDetailsJSONv2}",
    "ProblemURL":"{ProblemURL}"
}

My problem is that the array is too large for the tool that is picking this up. Ideally I'd like to grab only what I need from the ProblemDetailsJSONv2 placeholder.  I'm just not sure how to do this. 

"ProblemDetailsJSONv2":"{ProblemDetailsJSONv2}.evidenceDetails.details.properties.'dt.event.description'"

This doesn't work and doing it within the braces doesn't work either. 

Any help?

[ChadTurner]

@mrw I'd recommend putting in a RFE with the other tool that is getting this payload. Otherwise you might need to sacrifice other segments of the payload to accommodate your need. Were you able to get a work around for this?