The ornamental design for a three-position swing, as shown and described.
FIG. 1 is a perspective view of a three-position swing embodying my new
design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a view in side elevation taken perpendicular to the plane defined
by one leg of the swing, all sides not shown being substantially
identical;
FIG. 4 is an elevational view of the swing showing one leg in end
elevation; and
FIG. 5 is an elevational view, as shown from the side opposite FIG. 4 .