The Group Selector node allows you to select a number of objects (geometry, cameras, lights) and collections and import them into the current tree of the V-Ray Node Editor. This node has no editable parameters.

UI Path: ||V-Ray Node Editor|| > Shader > Add > Selectors > V-Ray Group Selector

UI Path: ||V-Ray Node Editor|| > Object > Add > Selectors > V-Ray Group Selector

UI Path: ||V-Ray Node Editor|| > World > Add > Selectors > V-Ray Group Selector