Damian Erskine over at notreble.com has some excellent tips on how to gain fretboard knowledge. A lot of folks struggle with this. A lot of bass instructors struggle with how to teach it too. The big deal, is one approach doesn’t work for all students, even though the desired outcome is the same.
Personally I really like Damian’s approach, but I think a lot of that might do to the fact that I think in patterns… and have caught myself on more than a few times visualizing my fretboard should I be asked what notes are in a Gb-7b5 chord, albeit for more common keys, its automatic.
Some students on the other hand, might best approach this using a series of flashcards to get the note knowledge down for each chord, and then following such up with exercises on the fret board.
Another approach I’ve found helpful for some over the years is to grab a series of melodies, and have the student play them successively starting on each fret position. The next thing to do, is to tell them they just had a string break, and they need to play the melody missing a string (in each individual fret position). A final progression for students with 5 or 6 string basses, is to assign one string as a drone, and then have the students play the melodies, all the while keeping the drone going. Obviously one doesnt do this all in one session, nor make it the main focus for an extended period of time… but too slowly add fingerboard knowledge as the students experience grows.