Yes, this is a hard sentence. Let's try to break it down. "[In this respect], [to even speak of Hong Kong cinema] [falsely imposes boundaries that] [ (the global reach of mass media) renders largely irrelevant]." A very simple version of this sentence is, "The boundaries are rendered irrelevant." What kind of boundaries? How irrelevant? "The falsely imposed boundaries are rendered largely irrelevant." What renders the boundaries irrelevant? The global reach of mass media. So, "The falsely imposed boundaries are rendered largely irrelevant by the global reach of mass media." What imposes the boundaries? Speaking of Hong Kong cinema. Therefore, "To even speak of Hong Kong cinema falsely imposes boundaries that the global reach of mass media renders largely irrelevant." I hope this helps break it down for you. I think this sentence could have been better written, but it is good practice to understand how these clauses fit together!