If you have tried reaching it with needle nose pliers, and that didn’t work I have a method that will work.
Get a tubing cutter (the kind with a little cutting wheel and rollers, like you use to cut brake line) and cut the dipstick tube below the point where the stick is broken. Once the dipstick is removed from the engine, remove it from the piece you cut off, then get a new dipstick from the dealership or a salvage yard. Use some J-B Weld to reattach the piece of the dipstick tube you cut off, being careful to only apply it to the outside of the tube. Butt the pieces together and fill the stuff around the cut to join the two pieces together. Once the J-B Weld cures then you should be good to go.