I was trying to narrow my search of documentaries to religious documentaries, but there is no way to limit my search. I like that you have an option to limit by genre, but you should ofter to limit it further, and further, if possible. Thanks.
On any page click the arrow next to the spyglass and select "Keywords". Since you are looking for religious documentaries, enter religious into the search box and click the spyglass (or hit return). This will bring you to:
You can further refine the search by choosing addition genres or by selecting another keyword further down on the right side of the page, for instance "Spiritual".