Currently it isn't possible to see all ad campaigns that a contact has been part of. It'd be great if such a feature could be available on the righthand side bar in the contact record.
There are two workarounds, but they are not very effective:
Use the "First touch converting campaign" or "Last touch converting campaign" property, and add this to the contact record's left hand sidebar → Limitation is that it only shows the first/last campaign, and not all
Navigate to Campaign Analytics, in the Traffic Analytics tool or use the ads tool → Limitation is that we cannot easily see all campaigns a contact has been part of