Event registration missing from Engagement History

Why can we no longer see which campaign a contact has signed up for... I have several campaigns and in the past, I was able to type in my contact and it would show which campaign they registered for.    With the change, that is no longer available.  On a chat yesterday, I was told I would need to use segments?  When I looked into that, it appeared I would need to create a segment, then tag my contacts with that segment?    So that means I would need to go through each one of my contacts and tag them.  That doesn't make sense as I don't know which campaign they are in, so I would have to go through each of my campaigns to find out what they signed up for.  At that point, I already have my answer.  Is there an easier way??

Sheila Re