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 display screen or portion thereof with transitional graphical user interface showing a first image in a sequence, showing our new design;
FIG. 2 is a front view showing a second image thereof;
FIG. 3 is an enlarged view of the claimed portion in FIG. 1; and,
FIG. 4 is an enlarged view of the claimed portion in FIG. 2.
The outermost broken lines illustrating portions of a display screen or portion thereof form no part of the claimed design. The dot-dashed broken lines define the boundary of the claimed design and form no part of the claimed design. The remainder of the broken lines illustrating portions of the graphical user interface forms no part of the claimed design.
The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1-2. The process or period in which one image transitions to another image forms no part of the claimed design.