DVT e Language IDE User Guide
Rev. 19.1.34, 11 October 2019
A diagram is created around a set of relevant structs you specify. For example when you decide to show parents, children or associations (from UML Diagrams - Preferences) it applies only to selected structs. In a diagram the selected structs are colored with yellow fill (see also the UML Diagrams - Legend ).
The right list shows the selected structs. Use left/right arrows or double click to select the relevant classes.
You can also add/remove an element to/from the current selection by right clicking on it in the diagram and choosing "Select Type"/"Deselect Type":