The ornamental design for a displayscreen or portion thereof with graphical user interface, as shown and described.
The FIGURE is a front view of a display screen or portion thereof with graphical user interface, showing our new design.
The dashed broken lines showing portions of the display screen or portion thereof with graphical user interface are for environmental purposes only and form no part of the claimed design.
The evenly spaced dashed broken lines illustrate the remainder of a display screen or portion thereof and form no part of the claimed design. The dot-dash broken lines in the figure illustrate a boundary of the claimed design, and form no part thereof.