A cascading List of Values (LOV) means that the values of one list should be refreshed if the value of one list on this page gets changed. For example value of the State, drop-down depends on the value of the selected Country.
To meet this requirement, I have captured a short video on this that will help you to achieve Cascading List of Values (LOV) in Oracle APEX.
Click on the below link and view the complete video:
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