I'm sure this is 'old hat' to many of the experts here, but.......
we just integrated MailChimp with our HS Sales Pro and want to create some reports and automations. HS documentation touts this as a possibility, however as I have dived into the Workflows it appears as if the only marketing email data that is available are those related to emails created and sent from HS. Same looks true in the Report Builder.....
What use case are you missing specifically ie. what automation you are trying to set up? We at Outfunnel have built a 3rd party HubSpot-Mailchimp integration, if you shared more details I could tell whether it'd be of use here or not (and at the minimum I'd learn about a new use case).
I have discovered that some basic automations are possible. When creating an enrollment trigger, the option to choose Mailchimp data is possible:
However, the specific options for the trigger (i.e. name of email campaign, email subject, etc.) have to typed in... HS does not import the associated Mailchimp data. And, of course, in the ever complex HS pricing strategy, only some actions are available for the Sales Hub vs. Marketing Hub, etc... HS loves to say that Sales Hub has workflows, but it only has a few when compared to marketing....