We claim the ornamental design for an attachment nozzle for a handheld hair styling device, as shown and described.
FIG. 1 is a front perspective view of an attachment nozzle for a handheld hair styling device showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a side view thereof;
FIG. 5 is a side view of the opposite side of FIG. 4;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines shown in the drawings illustrate portions of an attachment nozzle for a handheld hair styling device that form no part of the claimed design.