You can access the Scene Assembly menu from the Outliner or the scene view. The options available depend on whether you have a scene assembly node selected in the Outliner.
Turn on Asset centric selection in the Preferences window. See Selection preferences.
Selecting the representation selects its assemblyReference node.
-click the representation and select Select Assembly from the menu that appears.
You can now access the Scene Assembly menu by
-clicking the representation and selecting it from the menu that appears.
-click an empty area in the Outliner to access the Create Assembly Reference and Create Assembly Definition commands.
-click in the Outliner or scene view to access the node options in the Scene Assembly menu.
To access the following Scene Assembly menu items, select an assemblyReference or assemblyDefinition node, then
-click in the Outliner or scene view. Select Scene Assembly from the menu that appears.
Removes the current object displayed as a representation from the scene view, and sets the Active Representation to None. See Unload active assembly representations.
Displays a list of edits to the representation of a nested assembly reference node. See List Assembly Edits window.
Scene assembly edits are managed by the assembly reference nodes. See Scene assembly edits.
Add Cache representation, Add Locator representation, Add Scene representation
Adds the specified representation type to the selected assemblyDefinition node. See Add assembly representations.