Tree Views
A Tree View is an alternative method of viewing records to a Scan Form. A scan form uses a tabular format sometimes referred to as a data grid, a tree view displays records in a pre-defined structured hierarchy.
When in change mode in a detail form a burger stack may be displayed next to a field allowing data lookup to be performed;
Clicking on this icon will display a Tree View Form which provides a structured system for locating and selecting records.
Although the actual Tree (or hierarchy) display may differ depending upon system configuration, the key elements will remain identical:
Click; 
to expand a line.
Click; 
to collapse a line.
Click;
to open the record in detail view.
More:
Tree View Navigation