The ornamental design for a model of nestedgeometricforms as shown.
FIG. 1 is a perspective view.
FIG. 2 is a for reference only (showing the primary components) view.
FIG. 3 is an isometric view (view is perpendicular to the octahedron face); and,
FIG. 4 is top, bottom, right, left, front and back side view (view is perpendicular to the cube face).
The broken line showing of the individual elements of the model of nested geometric forms is for illustrative purposes only and forms no part of the claimed design.