The ornamental design for a waistbandexpander with a covering portion, as shown and described.
FIG. 1 is a perspective view of a waistband expander with a covering portion, showing my new design in a condition of use and in an open configuration;
FIG. 2 is an enlarged perspective view thereof, illustrated in a condition of use and in a folded-over configuration;
FIG. 3 is a top plan view of FIG. 2;
FIG. 4 is an enlarged perspective view thereof in a flat configuration;
FIG. 5 is a front elevational view of FIG. 4;
FIG. 6 is a rear elevational view of FIG. 4;
FIG. 7 is a left-side elevational view of FIG. 4;
FIG. 8 is a rear elevational view of FIG. 4;
FIG. 9 is a top plan view of FIG. 4; and,
FIG. 10 is a bottom plan view of FIG. 4.
The evenly spaced broken lines represent stitching and are part of the claimed design. The dot-dash broken lines showing the vertical buttonhole represent portions of the article that form no part of the claimed design. The remaining dot-dash broken lines depict environmental matter and form no part of the claimed design.