The ornamental design for a clip for a beltdecoration, as shown and described.
FIG. 1 is a rear perspective view of a clip for a belt decoration showing my new design. The broken line showing of the front of the clip is included for the purpose of illustrating an environment that forms no part of the claimed design.
FIG. 2 is a rear elevational view thereof.
FIG. 3 is a left side elevational view thereof, with the right side elevational view being a mirror image of FIG. 3.