We claim the ornamental design for a display screen or portion thereof with graphical user interface, as shown and described.
The sole FIGURE is the front view for a display screen or portion thereof with graphical user interface showing our new design.
The broken lines in the Figure show portions of the display screen or portion thereof with graphical user interface which form no part of the claimed design.
The dot dash lines in the Figure represent a boundary line and form no part of the claimed design.