The ornamental design for a displayscreen or portion thereof with transitional graphical user interface, as shown and described.
FIG. 1 is a front view of a first image in a sequence according to a first embodiment of our design for a display screen or portion thereof with transitional graphical user interface;
FIG. 2 is a front view of a second image in the sequence thereof;
FIG. 3 is a front view of a third image in the sequence thereof;
FIG. 4 is a front view of a fourth image in the sequence thereof;
FIG. 5 is a front view of a first image in a sequence according to a second embodiment of our design for a display screen or portion thereof with transitional graphical user interface;
FIG. 6 is a front view of a second image in the sequence thereof;
FIG. 7 is a front view of a third image in the sequence thereof; and,
FIG. 8 is a front view of a fourth image in the sequence thereof.
The appearance of the claimed design transitions between the images shown in FIGS. 1 through 4 in the first embodiment and between the images shown in FIGS. 5 through 8 in the second embodiment. The process or period in which one image transitions to another forms no part of the claimed design.
The broken lines in the drawings are for the purpose of illustrating a display screen or portion thereof and portions of the graphical user interface that form no part of the claimed design.