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I am starting a directory website. The biggest issue that I am having is trying to figure out which keywords to use and how to optimize for them. I am using Wordpress and we have overall category pages, such as Hair & Beauty. And then we have filters for users to reach subcategories such as, Skincare. My problem is that these subcategories are not actual pages, when the filter is used it just returns businesses within that category that have been marked to show for that filter. The URL doesn't change or it doesn't take you to a new page. So, I am trying to determine how do I optimize for my subcategory keywords if these aren't technically pages?