The ornamental design for a displayscreen or a portion thereof for a graphicaluserinterface, as shown and described.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.
The FIGURE is a front view of a display screen or a portion thereof for a graphical user interface showing our new design.
The broken line showing of a display screen forms no part of the claimed design.