Nigel Farage has been on Question Time 33 times, more that any other panellist. Here's an example
article from a Scot Nationalist news site which complains about exactly the opposite bias in a recent Question Time episode, a "Brexiteer-heavy lineup" as they put it, and a "serious breach of impartiality". You can say of course the Scot Nats would see it from that side, which is true, but they clearly think they're right and no-one's going to convince them otherwise.
As for examples of other perceived BBC news bias, I have lefty friends who see nothing but right wing bias. Recent examples include continuous negative coverage of China and Russia, emphasising only human rights abuses, corruption, interference in other countries, and lack of press freedom, and coverage of anti-Maduro protests and huge poverty problems in Venezuela while ignoring western sanctions that have helped put the country in its current state. Long standing complaints are the automatic coverage of the monarchy at the expense of news more important to most of the population, and the assumed importance of "city" matters, for example reading out the FTSE 100 index and share movements in news broadcasts. As one lefty friend commented, people laugh at how in the old soviet union they would dutifully read out tractor production figures in news broadcasts, but reading out share prices is seen as perfectly normal.
Those aren't my views, and I'm not saying there's right wing bias in BBC news. I'm just pointing out that different people see a completely different bias when presented with the same evidence. I think it's easy to ignore or overlook aspects of news coverage we agree with as neutral, and only notice the parts we disagree with, giving the end impression that it was generally biased the other way.
It's probably also a mistake to see Brexit as a right vs left issue (to me "liberal" means wishy washy centre ground, and it seems to have come over from the US as another word for left wing). Remember that many of the early objectors to the UK joining the EEC were from the hard left, who saw the EEC as a capitalists' club. Tony Benn is the obvious example, and Jeremy Corbyn and Seamus Milne are from the same mould, which probably explains why Labour is having such problems at the moment trying to keep younger pro-remain members happy.