This can be used to make search controller in header of tableView

SearchController+FilteredResult.swift

// UIViewController class conforms UISearchResultUpdating

 // MARK: Search Controller
    func configureSearchController() {
        searchController.searchResultsUpdater = self
        searchController.dimsBackgroundDuringPresentation = false
        definesPresentationContext = true
        tableView.tableHeaderView = searchController.searchBar
    }
    
    func filterContentForSearchText(_ string: String, scope: String = "All" ) {
        filteredSearch = dropboxListFolder!.filter { item in
            return item.name.lowercased().contains(string.lowercased())
        }
        tableView.reloadData()
    }

// Conformity
    func updateSearchResults(for searchController: UISearchController) {
        filterContentForSearchText(searchController.searchBar.text!)
    }