Display Screen or Portion Thereof with a Graphical User Interface

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

FIG. 2 is a second view thereof; and,

FIG. 3 is a third view thereof.

The outermost dash-dash broken line showing of a display screen or portion thereof in the drawings is included for the purpose of illustrating the display screen or portions thereof that form no part of the claimed design. The remaining dash-dash and dot-dot broken lines are included for illustrating portions of the graphical user interface that form no part of the claimed design.

The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1 - 3 . The process or period in which one image transitions to another image forms no part of the claimed design.