How do I snap a track segment to another?

Hi everyone,

I'm using Garageband to edit some raw drum tracks with my desktop iMac. They were imported as raw audio files, so they don't follow Garageband's metronome, timeline guides, etc.

I need to insert a couple of drum fills in the middle of the main drum track. My problem is this... I split the main drum track and separated the two pieces to insert the drum fill in the middle. However, I can't figure out how to snap the drum fill to the end of the previous track or to the beginning of the next track.

In summary, is there a way to position a track precisely right after the end of a track or right before the beginning of another track? It's very difficult to do this manually. I am only able to snap tracks to the timeline guides, but not to another track.

Thanks!