The ornamental design for a displayscreen 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; and,
FIG. 2 is a front view of a second embodiment of a display screen or portion thereof with graphical user interface.
The long-short broken lines showing the display screen and the dashed broken lines showing the remainder of the graphical user interface form no part of the claimed design.
The different stippling patterns are claimed subject matter that indicate a contrast of appearance.