Email archiving for compliance requirements

We have a business unit which has compliance regulator requirement to archive emails for 7 years (beyond the default of Eloqua's 2 years).

We use SMARSH archiving to meet this requirement How to Set up Email Archiving (smarsh.com).

So that we don't archive the entire instance and only capture the specific BU, we are wondering if Eloqua supports 3rd Party Journaling filtering e.g. by email group or security group which we use to distinguish different BUs with different archiving rules.

Has anyone else found solution for archiving compliance needs for different BUs in the same instance of Eloqua?

Thank you!