Cedric swept the city with his senses while leisurely visiting places as if he were a tourist.
He knows that the cultists he's helping to catch are panicking because of the sudden exposure they're experiencing. It was a stark opposite of how he was doing, and it paints a funny picture.
Still, none of the cultists had any idea that Cedric was the main reason why they were being located anywhere they hid in this city. He trusted Arishem and his group to keep his identity private so he wasn't worried at all.
After a week of scouting, Cedric located almost all of the hidden bases of the cult. He initially expected to experience some difficulty in doing so, since he only discovered them by chance during the first time, but as he went in with a clear goal in mind, he was able to locate them pretty easily.