The ornamental design for a displayscreen or portion thereof having a graphicaluserinterface, as shown and described.
FIG. 1 is a face view of an electronic device with display screen having a graphical user interface, showing a first embodiment thereof.
FIG. 2 is a face view of an electronic device with display screen having a graphical user interface, showing a second embodiment thereof.
FIG. 3 is a face view of an electronic device with display screen having a graphical user interface, showing a third embodiment thereof.
FIG. 4 is a face view of an electronic device with display screen having a graphical user interface, showing a fourth embodiment thereof; and,
FIG. 5 is a face view of an electronic device with display screen having a graphical user interface, showing a fifth embodiment thereof.
The inner vertically-oriented round-cornered notched broken-line rectangle illustrates the perimeter of a display screen. The broken lines outside this perimeter illustrate portions of an electronic device. The broken lines within this perimeter illustrate portions of a graphical user interface. The broken lines form no part of the claimed design.