Sorry but I'm not too familiar with SharePoint so hopefully my terminology is correct. From our Document Library we are trying to create two separate Lists, that will display various documents. These two Lists will each have 4 Subjects with various sub-Categories (no more than 3). I thought I found a solution by modifying the view of the page and using the Filter option. The problem was that I needed a few more lines of Filters. I did find this post that sounds like Option 1 of ECM4D's answer would suit our needs:
"1. Simplify your filter query with calculated fields. When you have complex queries it is good practice to create calculated columns with formula which has some boolean logic of the view and returns TRUE or FALSE results, and then you can create views using these calculated column(s). This technique is highly recommended because can help you to strongly simplify your queries and improve performance."
Can someone provide a few more details or an example of how this would be done? Or point me in the right direction? Thanks! :)