Use a technique for playing in a rule to try your JSONPATH params.
val rawjson = '{"Observation Time": "2021-11-06T11:06:00Z", "Forecast Time": "2021-11-06T11:52:00Z", "Data Format": "[Longitude, Latitude, Aurora]", "coordinates": [[0, -90, 5], [0, -89, 0]] }'
var results = transform("JSONPATH", "$.coordinates.[1].[1]", rawjson)
logInfo("test", " simple path to one value: " + results)
results = transform("JSONPATH", "$.coordinates.[?(@.[1]=='-89')].[1]", rawjson)
logInfo("test", " selective path to one value: " + results)
Partial example of searching