The ornamental design for a portion of a shoe upper, as shown and described.
FIG. 1 is a front perspective view of an embodiment of a portion of a shoe upper showing a new design;
FIG. 2 is a side view of the portion of a shoe upper of FIG. 1;
FIG. 3 is a top view of the portion of a shoe upper of FIG. 1;
FIG. 4 is a front view of the portion of a shoe upper of FIG. 1; and,
FIG. 5 is a rear view of the portion of a shoe upper of FIG. 1.
The area within the solid and dot-dash-dot lines forms the claimed design. The area within the broken lines is environmental and forms no part of the claimed invention.