Adding Merrill investment account from BOA account to Quicken

Select "Merrill Lynch Investments" as the bank (not BoA) when creating the account. Provide your Merrill Lynch login credentials when asked. If you don't already have a login with Merrill Lynch you'll need to create one, I don't remember exactly how I did that when I set up my IRA.

Basically, just treat it as if it were a Merrill Lynch account and ignore that there's any connection with BoA.