Movie Scene Sequence Player Nodes

Could somebody shed some light on how to use, or cast to a Movie Scene Sequence Object Reference? There are some Blueprint nodes that are of interest to me but I’m not sure what the relationship is, or how to establish one, between Level Sequences and Movie Scene Sequences. Basically, what is a Movie Scene and how are they used in Blueprints? I cannot find any documentation on this class and how they relate to Level Sequences / Master Sequences.