Donut Polygons

To provide compatibility with the import and export of GIS donut polygons, string and polygon tools may be used to create, combine, split, and modify multi-part or donut polygons.

When a single polygon is selected, from the right-click menu, select New Part to draw a string to be attached to an ordinary polygon or a donut polygon.
When more than one polygon is selected, from the right-click menu, select Combine Polygon Parts to create a multi-part or donut polygon by combining two or more parts.
Conversely, when a multi-part or donut polygon is selected, from the right-click menu, select Separate Polygon Parts to split the parts into independent polygons.

A second click on an already selected multi-part polygon will select the individual part. This creates a partial selection exactly as if you dragged along part of the polygon. This is useful for deleting or moving the parts of a multi-part or donut polygon.

Note: The polygons you select must all be in the same layer. Not all string editing tools may work on multi-part or donut polygons. If a tool you want to use on a multi-part or donut polygon is not enabled, you may need to separate the parts first and then combine them using the tools described above.

To create a donut polygon when both the outer and inner polygons have already been defined:

Select the outer and inner polygons.
Right click and select Combine Polygon Parts.

Alternatively:

Select the outer and inner polygons.
Run the Polygon Boolean | Difference tool on the Design tab, in the Tools group.

To create a donut polygon and keep the inner polygon:

Select the outer polygon.
Select New Part from the right-click menu.
Enable snapping and digitise the inner polygon.
Select the outer and inner polygons and select Split All from the right-click menu.