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 according to a first embodiment.

FIG. 2 is another front view thereof according to a second embodiment.

FIG. 3 is another front view thereof according to a third embodiment.

FIG. 4 is another front view thereof according to a fourth embodiment; and,

FIG. 5 is another front view thereof according to a fifth embodiment.

The outermost broken lines in the figures show a display screen or portion thereof, or an electronic device having a display screen, and form no part of the claimed design. The other broken lines in the figures show portions of the graphical user interfaces that form no part of the claimed design.