ITreeSelect is a hierarchical selection component. Compared to the vuetify list group component it only adds expanded parts of the hierarchy to the DOM, which is crucial in order to handle large datasets.
Use the emited selection-summary to keep track of the selection.

ITreeSelectItems may be set to an inactive state or to a non-selectable state and ITreeSelect reflects this by showing an item greyed out in the former and with no checkbox in the latter case.
ITreeSelect is built to be used with data coming from an external API which takes care of the search term filtering, which is not done in this example.