This is an example of how to add a category filtering function to the search box of the Shopify theme "Dawn" like the PC version of Amazon. By using the filtering filter that can be set on collection pages, you can perform keyword searches within a specified range.
Example of setting the search form of the theme "Dawn" to have one of the narrowing filters like a category search
[How to set it up] Add a custom Liquid section to the header group in the theme editor and insert the code
