The ornamental design for a displayscreen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front elevational view of a display screen or portion thereof with graphical user interface; and,
FIG. 2 is another front elevational view thereof, but shows without the broken line showing of portions of the graphical user interface.
The outermost broken lines in FIGS. 1 and 2 show a display screen or portion thereof, and form no part of the claimed design. The other broken lines in FIG. 1 show portions of the graphical user interface that form no part of the claimed design.