Go to admin CATALOG -> Categories then click Add Subcategory button
then you fill Category Name, click Products in Category tab and select the products you want to assign to this category
refer more here
Then refresh Magento Cache
Go to admin CATALOG -> Categories then click Add Subcategory button
then you fill Category Name, click Products in Category tab and select the products you want to assign to this category
refer more here
Then refresh Magento Cache