Ok, to simplify this entire head ballet, let's read it backwards so it makes more sense. Otherwise it's easy to get overwhelmed:
It basically says two and a half things:
1. One group must give notice 30 days after dishonor OCCURS. With respect to any other instrument, notice of dishonor must be given within 30 days following the day on which dishonor occurs.
2. In english, if a check (written by Bob to Joe) is given by the recipient to a bank that it was NOT drawn on (lets say a wells fargo check from Bob was deposited in Joe's BofA account) and wells Fargo gives Notice of dishonor to BofA, BofA has until the end of the next banking day to notify Joe of the dishonor or he is not obliged to perform under rcw 62a.3-415 (A).