Display screen or portion thereof with a graphical user interface

A portion of the disclosure of this patent document contains material to which a claim for copyright is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all other copyright rights whatsoever.

FIG. 1 is a front view of a first embodiment of a display screen or portion thereof with a graphical user interface; and,

FIG. 2 is a front view of a second embodiment of a display screen or portion thereof with a graphical user interface.

The outer broken line rounded rectangle illustrates a device or portion thereof and forms no part of the claimed design. The second perimeter rectangle shows a display screen or portion thereof and forms no part of the claimed design. All other broken lines show portions of the graphical user interface and form no part of the claimed design.

The stipple shading in the drawings indicates a contrast of appearance.