There IS a find and replace, actually, but there are two main things that throw people off (which probably means we should fix…):
The location: It’s on the right-click menu in the groups panel. You can right-click a group to only search it, or right click in general without a group selected in order to search everything.
Results: It actually only searches groups that aren’t logging. The reason for this is that you can’t change groups that aren’t stopped, but unfortunately… if you’re just trying to search you might get the impression that something wasn’t there when it really was.
Of course, another option would be to export to CSV (also on that same right-click menu), and then just do a search and replace there, and then import it back in.
Hope that helps,