Breakdance has multiple methods for duplicating an element in the builder.
The fastest way to duplicate a selected element is by using the Command/Control + D keyboard shortcut. This will duplicate the currently selected element.
You can also duplicate the currently selected element by right clicking it and clicking “Duplicate” in the context menu, or by clicking the duplicate icon at the top of the Properties panel.
If the element is not easily selectable or is hidden behind another element, you can duplicate it via the Structure panel by hovering over the element’s name and clicking the duplicate icon.