Placing concatenated string into output array

Input

{
	"id": "01001",
	"name1": "Larry",
	"name2": "Bird",
	"content1": "Basketball",
	"content2": "Court",
	"content3": "Stadium"
}

Spec

[
  {
    "operation": "shift",
    "spec": {
      "content1": [
		    "sports[1].name",
        "player.details[0].sport"
      ],
      "content2": "sports[0].location",
      "id": "player.id",
      "name1": "player.firstname",
      "name2": "player.lastname"
    }
  },
  {
    "operation": "modify-default-beta",
    "spec": {
      "player": {
        "details": {
          "0": {
            "fullname": "=concat(@(1,name1),' ',@(1,name2))"
          }
        }
      }
    }
  },
  {
    "operation": "default",
    "spec": {
      "player": {
        "details[]": {
          "0": {
            "teamname": "Celtics"
          }
        }
      }
    }
  }
]

Output

{
  "sports" : [ {
    "location" : "Court"
  }, {
    "name" : "Basketball"
  } ],
  "player" : {
    "details" : [ {
      "sport" : "Basketball",
      "teamname" : "Celtics"
    } ],
    "id" : "01001",
    "firstname" : "Larry",
    "lastname" : "Bird"
  }
}

I am attempting to get the full name placed in the details array in the player object. I have a feeling it has to do with navigating the tree, but I have been unable to get the values. If you see where this went wrong, your assistance would be greatly appreciated!

[milosimpson]

Yeah, each operation takes as input the output from the operation before it. Its a transform pipeline.

[blkdragn77]

Thank you for the information! So, in a chain spec, the first operation can see the source JSON. I am assuming the operations are executed in order. So, the source JSON is available for the 1st operation, the result of that is available to the 2nd, and so on…right? Just trying to better understand the mechanics of how operations are processed and what data is available where.