If you configured a view to display one or more hierarchies, a plus sign 
appears to the left of the first column heading in the view. Also, a plus sign appears next to a record if you place your mouse cursor over this column in a particular row (as shown in figure).
Click this + sign to the left of a record to display the list of hierarchies that you added to this view.
Click the + sign to the left of a hierarchy heading to open the sub-view and display the records related to the top-level record via the selected hierarchy. In igure, the hierarchy displays the Contact Logs for the specified Persons record.
- Note that if only one sub-view is defined for the view, opening the parent node opens the sub-view automatically.
You can double-click any record in the sub-view to open its corresponding form to see additional data or to make changes to that record. If you open a sub-type record from a -hierarchical view, edit it, and then save your change, the system also automatically saves the top-level record to reflect this change.
To collapse an expanded hierarchy, click the negative (-) sign to the left of the record or to the left of a hierarchy heading. Alternatively, you can click the Collapse All button to close all hierarchies or click the Refresh button to refresh the view and collapse all open hierarchies.
A view can support multiple levels of hierarchies. If the View you specified for a hierarchy in the Managed View field has its own set of hierarchies, you can view those as well.
.