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 outer perimeter illustrated by a pair of broken lines in the drawings represents a display screen or portion thereof and forms no part of the claimed design. The dot-dash broken lines define boundaries of the claimed design and form no part of the claimed design.