When viewing a repository which has an Xcode project or workspace from a Mac, users will see a new "Clone in Xcode" link on the clone dialog which allows them to directly open the project/workspace in Xcode.
"Clone in Xcode" will be automatically enabled for users who access Bitbucket Server using Xcode, but it can also be manually enabled by visiting your user profile. (Click avatar and select "Manage Account".)