Thread: How to indent subcategories in search bar?

How to indent subcategories in search bar?

How can I indent the subcategories in the search bar?

for example, I want to do this:

First Category
--subcategory 1
--subcategory 2
Second Category
--subcategory 1
--subcategory 2

Instead of this:

First Category
subcategory 1
subcategory 2
Second Category
subcategory 1
subcategory 2