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 first embodiment of a display screen or portion thereof with graphical user interface showing our new design; and,
FIG. 2 is a front view of a second embodiment of a display screen or portion thereof with graphical user interface showing our new design.
The broken-line rectangle at the periphery of the figures illustrates the perimeter of a portion of a display screen and forms no part of the claimed design. The remaining broken lines, including the script to the right of and below the play button symbol in FIG. 1, illustrate portions of the graphical user interface and form no part of the claimed design.