FIG. 1 is a rear perspective view of the composite seat cushion showing my new design;

FIG. 2 is top plan view of the composite seat cushion showing my new design;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear elevational view thereof,

FIG. 5 is a front elevational view thereof

FIG. 6 is the left side elevational view thereof; and,

FIG. 7 is the right side elevational view thereof.

All broken lines are for illustrative purposes only, and form no part of the claimed design.