WP Category Dropdown (wp-category-dropdown) free WordPress plugin

WP Category Dropdown plugin displays parent and child categories in a dropdown. You can select the parent category and display a dropdown for the child categories of the selected parent. If the selected parent category does not have a child category, you will be automatically directed to the category page.

You can use the shortcode or the widget to display the dropdown categories.

You can learn more at gcsdesign.com/wp_category_dropdown