We claim the ornamental design for a display screen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front view of a first embodiment of a display screen or portion thereof with graphical user interface showing our new design; and,
FIG. 2 is a second embodiment thereof.
The outer perimeter shown by a pair of evenly spaced broken lines in the drawings represents a display screen or portion thereof and forms no part of the claimed design.