Issue #3068584 by jhchnc, gapple, azussman: item_selector failing to grab a inner level JSON array.

Closes #3068584

tests/data/item_selector.json

@@ -3,11 +3,27 @@
   "data": [
     {
       "id": 1,
-      "title": "1 item"
+      "title": "1 item",
+      "items": [
+        {
+          "id": 1,
+          "title": "1.1 item"
+        },
+        {
+          "id": 2,
+          "title": "1.2 item"
+        }
+      ]
     },
     {
       "id": 2,
-      "title": "2 item"
+      "title": "2 item",
+      "items": [
+        {
+          "id": 3,
+          "title": "2.1 item"
+        }
+      ]
     }
   ],
   "data_empty": [],