The ornamental design for a displayscreen or portion thereof with 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 sole FIGURE is a front view of a display screen or portion thereof with a graphical user interface showing our new design.
The broken lines including alternating long and short dashes forming a frame around the graphical user interface are for the purpose of illustrating a display screen or a portion thereof that forms no part of the claimed design. The broken lines within the graphical user interface represent portions of the graphical user interface that form no part of the claimed design.