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 display screen or portion thereof with graphical user interface, showing my new design; and,
FIG. 2 is a front view thereof, in which a mobile terminal in broken lines is provided to illustrate an example environment.
The broken lines represent the display screen or portion thereof and forms no part of the claimed design.
The size and the scale of the design within the environment of use of FIG. 2 form no part of the display screen or portion thereof with graphical user interface.