Split and Join Selectively
Split and Join Selectively is a combination of OneView and JoinViews nodes, just like Nuke's vanilla Split and Join node, but it allows you to select which views are affected.
Using Nuke's Split and Join after a C_CameraSolver, for instance, splits and joins all views in the script, which can add unnecessary clutter to the Node Graph.
Adding Split and Join Selectively presents you with a dialog to select the required cameras manually or choose a preset, such as main and stereo.
In this example, only the left and right views are split out along side main, rather than all views.
Note: You can use Split and Join Selective after C_Stitcher as well, but remember to add a C_Blender after the join so that the views are recombined into a single stream. See Blending Multiple Views Together for more information.