Use the Boolean Explorer to keep track of operands when assembling complex compound objects. From the Boolean Parameters rollout, click Open Boolean Explorer.

Boolean Explorer with Example Operands
Operands automatically appear in the Boolean Explorer whenever you add an operand in the Boolean Parameters rollout. You can also drag objects from the scene explorer to the Boolean Explorer to add them as new operands. All changes to the order of operands and their operations in the Boolean Parameters rollout are automatically updated in the Boolean Explorer.
Selects all operands in the list.
Turns off all selections in the list.
Selects all operands currently not selected.
Enable to search for operands using case sensitivity.
Enable to search for operands using wildcards (* and ?).
Enable to search for operands using .
Expands all operand trees in the list.
Expands selected operand trees in the list.
Collapses all operand trees in the list.
Collapses selected operand trees in the list.
Selects the currently selected Booleans in the scene.
Locks all operands in the list, preventing any changes to be made.
Opens the Configure Columns window. Drag column headers to the window to remove them from the Boolean Explorer. Drag headers back to configure the columns to display.
Toggles the display of the Find, Selection, and Tools buttons below the menu bar.
Saves the currently configured layout as default.
Collapses selected operand trees in the list.