Format for Get Rest Value query results (json)

I have a GET_REST_VALUE query and am trying to create Keys to extract the results of the returned json values.   My returned values look something like this:

{
"count" : 65,
"dWs" : [ {
"dW" : {
"id" : 56,
"aC" : "J21",
"cc1" : "XX",
"wt" : 1
}
}, {
"dW" : {
"id" : 57,
"aC" : "J22",
"cc1" : "XX",
"wt" : 1
}
}, {
"dW" : {
"id" : 125,
"aC" : "M33",
"cc1" : "XX",
"wt" : 1
}
}, {
"dW" : {
"id" : 99,
"aC" : "DP1",
"cc1" : "XX",
"wt" : 2
}
} ]
}

And I am using something like this to try to extract values.

count
dws.dw.id
dws.dw.aC

The count extraction works fine, but the others don't.   What is the correct syntax for this and/or can you  point me at the documentation for it.   When looking at the GET_REST_VALUE docs, the format documentation for this appears minimal.