J-BusinessDirectory - Import multi-level categories

I am trying to import categories. I have about 500 and up to 4 levels of subcategories. The import tool only imports the first 2 levels. What would be the best way to import the rest? 

I tried sql import but I don't know how to populate the lft/rgt columns. If parent_id and level is set, is there a way to generate the lft-rgt columns after a sql import of the data? 

Hi,

It is possible to import multiple levels of categories.
The CSV file should be the following.

Level 1 category, Level 2 categories ( separated by comma)
Level 2 category, level 3 categories ( separated by comma)

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