To create a Nested Symbol, insert a Symbol instance into a Symbol Source on the Symbols page. Now, when you edit that Symbol instance’s Source, it’ll update anywhere, including the instances that are inside other Symbol Sources.
You can also create Nested Symbols by selecting two or more Symbol instances and choosing Create Symbol in the toolbar.
Note: There’s no limit to how many symbols you can nest within each other, but you can’t use an instance of a Symbol inside its own Source.
How to use Nested Symbol overrides
To use Nested Symbols so that they appear as overrides, you’ll need to have two or more Symbol Sources that are the same size and use one of these as a Nested Symbol.
When you select a Symbol instance in your design, you’ll see options to swap out Nested Symbols with any other Symbol that’s the same size. This is useful in a menu, for example, when you have buttons in a menu with active and inactive states.
To quickly access the Symbol Source for one of the nested overrides, click the arrow icon next to the Nested Symbol override’s name in the Inspector.