The category selection drop-down menu will look similar to the following:

TreeNodeChoiceField acts like ModelChoiceField; however, it shows hierarchical choices as indented. By default, TreeNodeChoiceField represents each deeper level prefixed by three dashes, ---. In our example, we have changed the level indicator to be four non-breaking spaces (the   HTML entities) by passing the level_indicator parameter to the field. To ensure that the non-breaking spaces aren't escaped, we use the mark_safe() function.