If you are wanting to split or divide a route or track on Garmin BaseCamp
1. Double click on the route or track in the bottom left hand pain to bring up either the route or track dialogue box.
2. If you click on either the way-points or track-points in the list you will see at what location they are at (orange circle appears around way-point) on the map.
3. Once you have found the way-point or track-point you want to split the route or track at just right click and select either 'split route here' or 'split track here' and this will create a second route or track.
4. Close route/ track dialogue box down and if you click on each of the routes or tracks in the bottom left hand pane it will identify which each are.
5. Rename if you wish to (right click and rename)
Video instructions and top tips for everything you need to know about Garmin BaseCamp can be found in the GPS Training online resource - more here