Hi eric,
When a question is far from the tutorial content, please use the Q&A forum, thanks.
It takes a few steps.
You need to give the Voronoi chunks a specific color, A Shader Effector limited by the MoGraph Selection.
This can be then read out from a User Data, MoGraph > Color
This User Data color goes into an RS Store Color To AOV while you specify a name for the AOV.
Setting up an AOV [Custom]
This will then render out the color information of the UserData, here as White, while the Voronoi Fracture> Transform was set to black.
Example
https://www.amazon.com/clouddrive/share/8NMRfB55l4P8V7aSD6u6cWcVt9d2jxQ4pCIl7SugNNd
A quick screen capture
https://www.amazon.com/clouddrive/share/02PrFOwnkzbA2gq18aA6Ehhgv4LuftGbYCthMhUhVSz
All the best