The ornamental design for a shelfdivider for dividing a shelf or a tray, as shown and described.
FIG. 1 is a top perspective view of the shelf divider for dividing a shelf or a tray showing my new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a top view thereof;
FIG. 4 is a bottom view thereof
FIG. 5 is a front view thereof;
FIG. 6 is a back view thereof;
FIG. 7 is a right side view thereof;
FIG. 8 is a left side view thereof; and,
FIG. 9 is a front perspective view thereof, the shelf divider shown in use.
In the figures, features shown by broken lines are for illustrative purposes only and form no part of the claimed design. Certain solid lines of varying length indicate surface shading and the lines themselves form no part of the claimed design.