You have opened a project.You have opened a page in the graphical editor. You have inserted a model view (Insert > Graphic > Model view) and placed it. In the Model view dialog, select the View tab and click [...] in the "Value" field of the property Model view: Selection scheme.
You use this dialog to create and manage schemes for displaying item types in the model view.
Overview of the main dialog elements:
Select the scheme that you wish to use or edit from the drop-down list. You can also use the adjacent toolbar for this purpose.
This part of the dialog is used to specify the criteria for automatic item selection.