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 shown in an environment with a monitor;
FIG. 2 is a perspective view thereof;
FIG. 3 is a front view of a display screen or portion thereof with graphical user interface shown in an environment with a tablet; and,
FIG. 4 is a perspective view thereof.
The broken lines showing the monitor in FIGS. 1 and 2 and the tablet in FIGS. 3 and 4 are included for the purpose of illustrating environmental structure; the broken line rectangle within the monitor or tablet showing the display screen; the broken line showing of the text within the display screen in all FIGS. is included for the environmental purpose only; all broken lines form no part of the claimed design.