In PoseMode, press Wkey or use the Pose pulldown menu. It calculates the positions of all selected Bone end points, over the time as indicated with the Scene start/end frame. This then is drawn as a path, with little black dots on every frame, and a white dot on every 10 frames. Paths are not saved in files, and not calculated automatic yet on changes. To make this relative fast, but also reliable, I had to add a new method in the Dependency graph system, to find exactly (and only) these parents of an Object that influence its position. This is needed because the path should show the actual global coordinates of the entire animation system.