We claim the ornamental design for a display screen or portion thereof with graphical user interface, as shown and described.
The sole FIGURE is a front view of a display screen or portion thereof with graphical user interface showing our new design.
The outer perimeter broken line in the drawing FIGURE represents a display screen or portion thereof and forms no part of the claimed design. The remaining broken lines in the drawing illustrate portions of the graphical user interface that form no part of the claimed design.