From what I read in this
PDF (I have no idea if this PDF is even remotely on target.) I think I understand your structure. Essentially, you have to create a type-definition in LabVIEW to match the C++ code. (A custom control, with the typedef attribute set.) I believe that you have created a cluster with an array of clusters of box coordinates. If you do not wish to put anything else in that packet, the wrapping cluster is probably not needed.
I think below is what you want. The image is a snippet of the dashboard VI. The zip file, contains the typedef'd control. Apparently, CD doesn't allow uploading of ctl files.
Dashboard TypeDef for basicxman.zip
Disclaimer: I am very rusty in C++, and don't have any sample data to test this.