Check out these 2 scenes from Way Of The Dragon and Fist Of Fury.
Although they are coreographed movie fights they are the best way to see Bruce's movement, technique and athleticism.
Many of the concepts of JKD can be seen here - footwork, angles, changing of levels, timing, interception, multiple opponents, weapons, defanging, etc.
Most important of all, use these clips to study his footwork and movement - then compare them to Ali - and Fred Astaire!