Audio Layers Merging?

I have a drive in which I edit videos on. I recently brought the drive to my other computer to edit on. Some files were missing, like voiceovers and such, but everything else was there. The main footage did not seem to sync properly, so I clicked "Replace Footage" and replaced it with the right footage. When it loaded in, all four audio layers it had before shows the exact same audio waves. Where they used to each show their own unique audio, one records my mic, one records my game, etc. I do not know how to fix this.