Hi Brooke,
Your question may have been answered via another resource.
It may be possible to reference the specific marketing list that the contact/lead is a part of, depending on if you are using separate marketing lists for each Campaign Automation. Since Workflows are a CRM functionality, we recommend reaching out to your CRM partner or CRM Admin for further information.
The ability to evaluate what Campaign Automations a specific contact or lead is in is coming up in a future release. For anyone interested in this feature release or other future feature releases I recommend signing up for our Product Announcements.