I claim the ornamental design for a display screen or portion thereof with graphical user interface, as shown and described.
FIG. 1 is a front view of a display screen or portion thereof with graphical user interface showing my new design;
FIG. 2 is another view of the design of FIG. 1, showing environment; and,
FIG. 3 is a front view of a second embodiment of the design.
The broken lines of the mobile terminal, text, words, numbers, and symbols are for the purpose of illustrating environmental structure, and form no part of the claimed design. The dash-dot lines in the figures form a boundary of the claimed design, and form no part of the claimed design.