What is the command for alphabetical Bookmark sort in Safari Version 11.0.3 ?

Install the latest Safari update, Safari v 11.1. https://support.apple.com/en-us/HT204416

Available for: OS X El Capitan 10.11.6, macOS Sierra 10.12.6, and macOS High Sierra 10.13.4

I haven't seen any command /shortcut posted yet.

Safari 11.1

Sort Bookmarks

1. Click Sidebar icon in Safari toolbar.

2. Right click the Folder to be sorted.

3. Scroll down to “Sort By’.

Choose “Name” from the pop-up menu.

You need Safari 11.1 to get that option. Go to the App Store and check for an update.