Display Screen or Portion Thereof with a Graphical User Interface

FIG. 1 is a front view of a display screen or portion thereof with a graphical user interface showing our new design, the front view showing a first image in a sequence of the graphical user interface;

FIG. 2 is another view thereof showing a second image in the sequence of the graphical user interface;

FIG. 3 is another view thereof showing a third image in the sequence of the graphical user interface; and,

FIG. 4 is another view thereof showing a fourth image in the sequence of the graphical user interface.

The outermost broken line illustrating an electronic device, the second outermost broken illustrating the display screen, and the remaining broken lines illustrating portions of the graphical user interface form no part of the claimed design.

The appearance of the graphical user interface transitions between the sets of images shown in FIGS. 1 - 4 . The process or period in which one image transitions to another forms no part of the claimed design.