Customize a Wordpress Navigation, and add search

Style a Wordpress Twenty Fifteen theme Navigation Add a search to the top of the navigation that provides a detailed results page Make menu collapsable and add support for menu and search in the theme functions file of an existing Twenty Fifteen child. Must work properly with the Dashboard Menu Structure. Need an effective menu design for 2-3 sub levels under the page title. Ensure dropdown Toggle arrows behave properly on focus. They should not move without purpose. Changes must adapt to current responsive Theme Example Would like to switch menu look and feel from this Twenty Fifteen theme [login to view URL] To this type of collapsable menu [login to view URL] Detailed examples will be provided to the top 3 Freelancers who bid on this project. If your bid does not mention the 3 key parts of this request, your bid will not be accepted. Am looking for Wordpress experts to build an ongoing relationship to the end of 2018. Please put a link to relevant samples in your bid. Thank-you for your interest, we are looking to procure the top 3 for further discussion into the details of this project.