1. Go to Contacts > Database Management > Attribute Setup > Segmentation
  2. Select the Segment Category you wish to contain the new segment, or click New > Segment Category to create a new category
  3. Click New, then click Segment
  4. Give the Segment a name and click Save
  5. Select the new segment by clicking on it
  6. Click Edit, then Query
  7. Build a query based on the criteria that you wish
The system will take the query of records and apply the segment to all those accounts. It can take up to 24 hours for the segment to apply across your database.

The query is considered to be Dynamic so the system will continuously update the list of records that you have set up in your query with the segment that you created the query for.  Please keep this in mind, as this could cause data to be added to accounts after the initial segmentation that you do not with to have applied.