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; and,

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

Shaded portions indicate a contrast in appearance. The outermost broken lines in the figures show a display screen or portion thereof and form no part of the claimed design. The even dashed ellipse around the head icon shows portions of the graphical user interface that form no part of the claimed design. The text shown in dashed broken lines(s) define the bounds of the claimed design and form no part thereof.