这应该可以达到目的：

let linkDetector = try! NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
let str = "hello at https://www.stackoverflow.com or http://google.com ?"

let attrStr = NSMutableAttributedString(string: str)

let matches = linkDetector.matches(in: attrStr.string, range: NSRange(location: 0, length: attrStr.string.utf16.count))

matches.reversed().forEach { aMatch in //Use `reversed()` to avoid range issues
    let linkRange = aMatch.range
    let link = (attrStr.string as NSString).substring(with: linkRange) //Or use Range
    //Here, you could modify the "link", and compute if needed myURLTitle, like URL(string: link)?.host ?? "myURLTitle"
    let replacement = NSAttributedString(string: "myURLTitle", attributes: [.link: link])
    attrStr.replaceCharacters(in: linkRange, with: replacement)
}

print(attrStr)