Use lists.
Create lists for different activities/times/whatever categorization you want to use and put the tracks belong to to that category in the appropriate list.
Then, when you select a list, only the tracks belonging to that particular list will be displayed.
Earl Horn,
Tracks, routes, waypoints are shown in both the list they are located in and My Collection.
By adding lists you organize these items. What you have done, however, is using a list for waypoints and another list for your tracks. I think you would be better of if you organize your items on a 'project' basis. What I mean is, create a list for project A and put all items (tracks, waypoints) that are related to that project in this list. Create other lists for similar projects.
Earl - are you manually searching your tracks for the correct timestamp / position to figure out where you too a particular photo?
If you like, you can try to select the track, right-click, choose 'Geotag Photos using Track...' and navigate to your photos folder for that track. Then BaseCamp will automatically set the correct location for these photos matching the time-stamp of the photo to the position of the track at that time.
Alternately if you have a whole folder or selection of photos you wish to locate consider using a program like Geosetter - it will batch geotag the photos for you. I tried importing one of my previously geotaged images into Basecamp and it worked like a charm.
Thanks Falagar for pointing me to the functionality in Basecamp - didn't even know it existed ! Must give it a go sometime.