I'm really new to BI and found this thread useful. Although, I still had to mess with it a little to figure it out. Here is a more step by step for a newbie like me:
1. Pick the camera you want to clone and go to its camera properties and on the General tab click Export down at the bottom. Make note of where this config file gets exported to. Then click OK to close this window.
2. Click the plus sign at the top of the main window to add a new camera. Two windows pop up. Click Cancel on the Network Configuration window. Then in the camera properties window go to the General Tab and push Import down at the bottom.
3. Find the file that you just exported and import it. Then you'll need to rename the camera and modify any other settings that you want to have different in this clone. When you are done you can make this clone hidden, so its not on your main view screen.
The way i'm using my clone: The original camera is recording everything on motion, so there are lots of false alarms like wind blowing trees and stuff, but that's ok, i don't want to miss anything. By cloning that camera I could narrow down a small area and make it less sensitive and then set it up to send me alerts, so that it only alerts me if someone walks up to my door. And i turned off recording on the clone, because the original is taking care of recording the whole area.
Hope this helps. I know this forum has been a huge help to me. Thanks to all the great contributors!