1.Nobody is following what being said.(somebody is saying something and at the same time nobody is following him/her).
2.Nobody is following what being said.(something was said earlier but now nobody is following).
Now if we don't use auxiliary 'is' in first sentence and 'was' in second sentence. They are the same. My question is we can use 'being+PP' without 'is' or 'are' as auxiliaries in first sentence but we have to use 'were' auxiliary in second sentence to show that something was said before