The ornamental design for a displayscreen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front view a display screen or portion thereof with graphical user interface showing our new design;
FIG. 2 is a front view of a second embodiment of a display screen or portion thereof with graphical user interface; and,
FIG. 3 is a front view thereof showing the second embodiment with additional broken line subject matter.
The outer broken lines show a display screen or portion thereof and form no part of the claimed design. The remaining broken lines show portions of the graphical user interface and form no part of the claimed design.