The ornamental design for a displayscreen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front perspective view of a display screen or portion thereof with graphical user interface showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a top view thereof; and,
FIG. 4 is a front perspective view thereof, showing additional unclaimed environment.
The dashed broken lines showing portions of the display screen or portion thereof with graphical user interface are for environmental purposes only and form no part of the claimed design.