You can't define the feature definition to use as the graphics are read in, if you are using the Selection Set method in this tool. However, once the nodes have been created, you can select them and change the feature definition, and you can do this for all of the nodes in one go.
The Extract tool includes a second method - Utility Filter. If you have 3D graphics which include a cell for the node, then you can use this method, and it does let you set the feature definition to use.
The Extract tool includes a second method - Utility Filter. If you have 3D graphics which include a cell for the node, then you can use this method, and it does let you set the feature definition to use.