The ornamental design for a displayscreen 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 the claimed design.
The peripheral dot-triple dashed lines depict a display screen or portion thereof, and form no part of the claimed design. The dotted lines within the peripheral dot-triple dashed lines depict portions of the graphical user interface which form no part of the claimed design.