Pablo Vazquez released a video on the official Blender youtube channel showcasing the new properties search feature that is currently being developed.
The search field can be found on top of the properties editor or can immediately be accessed through the ctrl+F shortcut. It works by highlighting matches (panels and sub-panels) and dimming all other fields.
Developer Hans Goudey, who had previously worked on the very popular bevel profiles and the new modifier panels among other things, has been working on the properties search implementation since June.
One fantastic byproduct of this feature is that the work done under the hood to make properties search possible has laid the ground-work to expanding search functionality into every nook and cranny of Blender, including the Blender Preference window ( Everything Search on the horizon?).
This feature is still under development, with many upcoming improvements already in the pipeline, including multitab search and fuzzy search!