A lot of patent applications never develop into actual products but in the case of this particular Oppo filing, it could be the real deal. A patent application filed at the end of March that included a set of schematics has now been updated with high-quality official-looking renders. This unannounced slider phone borrows from the existing Find X in that it stashes the selfie camera (likely cameras, plural) under the display when not in use, only it differs from the original on the back - the rear cameras remain exposed at all times here, and are in the top left corner. The Find X has them...
Source: https://www.gsmarena.com/oppo_patent_application_slider_phone_color_renders-news-38494.php