The ornamental design for a cap with a crownportion of three panels, as shown and described.
FIG. 1 is a perspective view of the cap with a crown portion of three panels showing my design;
FIG. 2 is a front elevation view thereof;
FIG. 3 is a back elevation view thereof;
FIG. 4 is a left side elevation view thereof;
FIG. 5 is a right side elevation view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The long dashed broken lines that depict the cap button, cap visor, and interior elements of the cap crown define portions of the cap with a crown portion of three panels that form no part of the claimed design. The short dashed lines along the interior of the cap crown in FIG. 7 define portions of the cap with a crown portion of three panels that form no part of the claimed design. The short dashed broken lines along the exterior surface of the cap depict features of the cap with a crown portion of three panels that form no part of the claimed design.