We claim the ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described.
FIG. 1 is a first image in a sequence for a display screen or portion thereof with transitional graphical user interface showing our new design;
FIG. 2 is a second image thereof;
FIG. 3 is a third image thereof;
FIG. 4 is a fourth image thereof;
FIG. 5 is a fifth image thereof;
FIG. 6 is a sixth image thereof;
FIG. 7 is a seventh image thereof;
FIG. 8 is an eighth image thereof;
FIG. 9 is a ninth image thereof;
FIG. 10 in a tenth image thereof;
FIG. 11 is an eleventh image thereof;
FIG. 12 is a twelfth image thereof;
FIG. 13 is a thirteenth image thereof; and,
FIG. 14 is a fourteenth image thereof.
The outer perimeter shown by dashed broken lines in the drawings represents a display screen or portion thereof and forms no part of the claimed design.
The appearance of the transitional image sequentially transitions between the images shown in FIGS. 1-14. The process or period in which one image transitions to another image forms no part of the claimed design.
The grayscale shading in the drawing figures represents a contrast in appearance.