odoo/addons/base_import/static/csv/External_id_3rd_party_application_product_categories.csv

1	External ID	Name	Parent Category/External ID
2	a1	Expenses	product.product_category_all
3	a2	Other Products	product.product_category_all
4	a3	Sellable Products	product.product_category_all
5	a4	Tables	a1
6	a5	Seating furniture	a2