Type the name of the episode, creator, user, list, or hashtag you're looking for into the white search bar at the top of the page. On the right side of the search bar, click "Everything." From the dropdown menu, select whether you want to search for creators, lists, episodes, users, or hashtags. Then hit your Enter key to start the search.
You can also toggle this setting from the Results page. Underneath Search Results, click the button on the left, that says "Creators," or whatever category you chose to filter by. Use the dropdown menu to toggle between options. Search results should automatically update when you make your selection.