Hi @atlantis1525,
To accomplish this, you can either write custom functions to display subcategories or use a plugin like Woolentor or a page builder such as Elementor to create a custom category page that also includes the subcategories.
If you’d like to show the subcategories in a sidebar, you can use the built-in WooCommerce Product Categories widget. Depending on your theme, access the sidebar and add the widget there. Then, adjust the settings to display the subcategories of the current category.