But what is a Bank Account doing in a Profit and Loss!?!  Bank accounts are assets and need to be in a Balance Sheet.

Maybe you are asking - how do I get a P&L from only those transactions that happened to be paid into or taken out of a particular bank account (or closer to your actual question - don't include income and expenses that went through a particular bank account).  Now that is an interesting question and if the solution provided below is the answer to that question I have seriously learnt something and is an explanation for those filter options I have never understood.  I will have to test it and think about when I might have a reason to use it.  Thoughts are starting to flow.  I'm an accruals man, so bank accounts have little role in management for me, but maybe a Liability or a Clearing account.  Tasty.