By default, LabVIEW limits the interactive selection of multiple items in a tree control to items that share the same parent. To allow the selection of items with different parents, right-click the tree control and remove the checkmark from the Selection Mode»Limit Multiselect to Siblings item in the shortcut menu. You also can use the Sibling Multiselect property to programmatically limit the selection of multiple items to siblings or to allow the selection of items with different parents.
If you limit the interactive selection of multiple items to siblings, you still can select items with different parents programmatically by using a local variable or setting the Value property of the tree control. However, you then cannot add new items to the selection interactively.
If you enable the Limit Multiselect to Siblings shortcut menu item, but there are multiple non-sibling items already selected, subsequent selection behavior might not be intuitive. If you reset the selection to something valid, the selection behavior returns to normal.