We need to be able to pull a Smart List with Address Line 1 (street address) and Address Line 2 (suite number) separated. We have tried setting up a Data Management program to keep the address filed in sync with two custom fields for line 1 and line 2, but we are running into a problem. We can combine the two fields, but we can't figure out how to split them back out when updates come from Salesforce.
You are probably going to have to do this in SFDC. I don't think it is possible in Marketo to the best of my knowledge.
Here is the answer to a similar question from a while ago: Splitting First Name Last Name from one field into two?