The ornamental design for a combinationhat and headband, as shown and described.
FIG. 1 is a front perspective view of a combination hat and headband showing my new design as it would appear when being worn as a hat;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a right side elevation view thereof;
FIG. 4 is a rear elevation view thereof;
FIG. 5 is a front perspective view of the combination hat and headband in an alternate position as it would appear when being worn as a headband;
FIG. 6 is a front elevation view thereof;
FIG. 7 is a right side elevation view thereof; and,
FIG. 8 is a rear elevation view thereof.
The broken lines represent environmental subject matter intended to show how the claimed design may appear when worn and form no part of the claimed design.