The ornamental design for a displayscreen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front view of the claimed design for a display screen or portion thereof with graphical user interface;
FIG. 2 is a front view of an alternative embodiment of the claimed design for a display screen or portion thereof with graphical user interface; and,
FIG. 3 is a front view of an alternative embodiment of the claimed design for a display screen or portion thereof with graphical user interface.
The outer rectangle in each drawing shows a display screen. the broken lines showing the display screen or portion thereof with graphical user interface depict environmental structure and form no part of the claimed design.