A quick segment is a segment you create within a chosen dimension.
1. Hover over the options icon next to a dimension, then click the Quick Segment icon.
2. The segment is added to the view. Click Save to open it in the Segment Builder.
3. The Segment Builder is automatically populated with the values of this segment. Save it to your library for later use.
This allows you to quickly filter to a dimension of interest. The default scope of the segment is Event, which in this example means the data is filtered to only those hits where the Device Type is equal to Tablet. To learn more about scope, see What is Segment Scope?