The ornamental design for a displayscreen or a portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front view of the first image in the sequence of the new design for a display screen or a portion thereof with graphical user interface; and,
FIG. 2 is the second image thereof.
The appearance of the animated user interface sequentially transitions between the images shown in FIGS. 1-2. The process or period between which one image transitions to another forms no part of the claimed design.
The broken line showing of the phone and the display screen or a portion thereof is for the purpose of illustrating environment and forms no part of the claimed design. The broken line showing of elements on the display screen illustrate portions of the graphical user interface and form no part of the claimed design.