You can configure a few Magmi plugins to format the data so that it can be processed correctly.
Make sure you have the On the fly category creator/importer enabled and the Tree level separator: configuration option set to
/
for the plugin.Enable the Column mapper plugin and add
Category,Sub Category
to the Mapped columns listFor the Category field (in the Column mapper plugin), enter:
category
For the Sub Category field (in the Column mapper plugin), enter:
subcategory
Your column mapper plugin configuration should look like this:
Enable the Value Replacer plugin and enter
categories
into the Replaced attributes field.For the categories field (in the Value Replacer plugin), enter:
{item.category}/{item.subcategory}
Your Value Replacer configuration should look like this:
Click Save Config and run your import.