When the parent document becomes composited, the layer trees should get connected together.

{
  "bounds": [800, 600],
  "children": [
    {
      "bounds": [800, 600],
      "contentsOpaque": true,
      "drawsContent": true,
      "children": [
        {
          "position": [8, 108],
          "bounds": [370, 220],
          "drawsContent": true,
          "children": [
            {
              "position": [35, 35],
              "children": [
                {
                  "bounds": [285, 150],
                  "children": [
                    {
                      "children": [
                        {
                          "bounds": [285, 230],
                          "children": [
                            {
                              "bounds": [285, 230],
                              "drawsContent": true,
                              "children": [
                                {
                                  "position": [18, 10],
                                  "bounds": [210, 210],
                                  "contentsOpaque": true,
                                  "drawsContent": true,
                                  "backgroundColor": "#0000FF"
                                }
                              ]
                            }
                          ]
                        }
                      ]
                    }
                  ]
                },
                {
                  "position": [285, 0],
                  "bounds": [15, 150],
                  "drawsContent": true
                }
              ]
            }
          ]
        },
        {
          "position": [8, 8],
          "bounds": [100, 100],
          "contentsOpaque": true,
          "drawsContent": true,
          "backgroundColor": "#0000FF"
        }
      ]
    }
  ]
}


--------
Frame: '<!--framePath //<!--frame0-->-->'
--------
{
  "bounds": [285, 230],
  "children": [
    {
      "bounds": [285, 230],
      "drawsContent": true,
      "children": [
        {
          "position": [18, 10],
          "bounds": [210, 210],
          "contentsOpaque": true,
          "drawsContent": true,
          "backgroundColor": "#0000FF"
        }
      ]
    }
  ]
}