The following article discusses how to define a polygon feature that supports holes.
Storing MicroStation polygons with holes using the XML Feature Modeling (XFM) data model, requires the definition of a Polygon Collection. This requirement is necessary since the the DGN file format does not have an explicit element type to store polygon with holes.
To define a Polygon Collection, create a new polygon feature and enable Create Feature Collection
Note that the Geometry_Area and Geometry_Perimeter values excludes the holes.
A sample schema is provided for your learning.
Polygons with holes.zip