Dot Walking to Customize Reports
Dot Walking can be used to customize reports that require information from multiple tables.
If you are creating a report off of a particular table, but would like to reference content on another table, you may be able to accomplish this with dot walking. Dot walking provides access to fields on related tables. If the current table contains a reference to another table, any field on the referenced table can be accessed using dot walking.
For example: The Incident table references the Assignment Group table, so you can dot walk to fields on the Assignment Group table when running a report on the Incident table.
Use the Show Related Fields option on any filter list to display your dot walking options.
It is not recommended that you dot walk across more than three tables at once.
Visit the ServiceNow wiki for a video tutorial and step-by-step guide on how to dot walk.