After you connect your MailChimp account to Cause Machine, you will be prompted to select an existing Audience from a drop-down list, or create a new Audience. Then, Cause Machine will push all of the members in your community to that audience and set custom profile fields, including their Membership Level. It will also tag that member with the name of the community they are a part of. You can either key off that tag to create a segment or create a segment from any of the custom profile fields that are created.
Here is an example of a what a contact will look like in MailChimp that is synced from Cause Machine: