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 a graphical user interface (GUI).
FIG. 2 is a front view of a display screen or portion thereof with a second embodiment of the GUI.
FIG. 3 is a front view of a display screen or portion thereof with a third embodiment of the GUI.
FIG. 4 is a front view of a display screen or portion thereof with a fourth embodiment of the GUI; and,
FIG. 5 is a front view of a display screen or portion thereof with a fifth embodiment of the GUI.
The outermost broken-line perimeter illustrates a display screen or portion thereof and forms no part of the claimed design. The remaining broken lines illustrate portions of the graphical user interface that form no part of the claimed design.