For getting the all of the latest and supported category hierarchy for a eBay marketplace, please follow the steps mentioned below:
1. Firstly, you need to call GetDefaultCategoryTreeId to retrieve a reference to the default category tree associated with the specified eBay marketplace ID.
2. After getting the category_tree_id make a GetCategoryTree call to retrieve the complete category tree that is identified by the category_tree_id parameter.
To learn more about the category tree structure, please take an overview of the Taxonomy API by going through the link given below:
eBay Developer Support
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