I claim the ornamental design for an expandable shelf steps, as shown and described.
FIG. 1 is a top perspective view of the expandable shelf steps, showing my new design.
FIG. 2 is a front elevational view of the expandable shelf steps.
FIG. 3 is a rear elevational view of the expandable shelf steps.
FIG. 4 is a side elevational view of the expandable shelf steps.
FIG. 5 is a right side elevational view of the expandable shelf steps.
FIG. 6 is a top plan view of the expandable shelf steps; and,
FIG. 7 is a bottom plan view of the expandable shelf steps.
The broken lines shown in the figures are for the purpose of illustrating portions of the expandable shelf steps and form no part of the claimed design.