We claim, the ornamental design for a display screen or portion thereof with graphical user interface, as shown and described.
FIGURE is the front view for a display screen or portion thereof with graphical user interface showing our new design.
The outermost broken line illustrates a display screen or portion thereof. The broken lines within the display screen or portion thereof, including all text, numbers, and indicia, illustrate portions of the graphical user interface. None of the broken lines form part of the claimed design.