Select the shape and set the disassemble level to disassemble into its sub-shapes.

The disassemble level can be selected from [Sub Shpes], [Solid], [Shell], [Face], [Wire], [Edge] and [Point].

Disassemble is applied to target shapes that have a higher rank than the disassemble level. In other words, if the shape is solid, it can be divided into shapes that have a lower rank than a solid such as [Shell], [Face], [Wire], [Edge] or [Point].

[Sub Shapes] is the option that disassembles the shape by the geometry rank just below it.

Compound shapes are a set of simple shapes and applying [Sub Shapes] disassembles each shape in the compound individually.

The geometry ranking is as follows: [Solid] > [Shell] > [Face] > [Wire] > [Edge] > [Point].  

For example, the sub-shapes of a shape consisting of faces and solids are as follows.

The properties of the selected shape can be verified from Tools > Show/hide > Properties.