In this video we’re going to take a deeper dive into the Fracture Mode “Embed” Tools. These tools are used to embed geometry elements, such as a rebar static meshes, into a Road surface geometry collection.
https://dev.epicgames.com/community/learning/tutorials/v7kR/fortnite-fab-unreal-engine-5-8-chaos-destruction-for-beginners-how-to-embed-geometry