sourceSegments property
The base segment to build the segment on. A base segment, also referred to as a source segment, defines the initial population of endpoints for a segment. When you add dimensions to a segment, Amazon Pinpoint filters the base segment by using the dimensions that you specify.
You can specify more than one dimensional segment or only one imported segment. If you specify an imported segment, the Amazon Pinpoint console displays a segment size estimate that indicates the size of the imported segment without any filters applied to it.
Implementation
final List<SegmentReference>? sourceSegments;