In that case I must report that it doesn't work on my MBA 6,2 running OS X 10.10.4. Right clicking (actually ctrl-clicking, given the Mac trackpad) doesn't show a contextual menu either on folders in the main Bookmarks menu, nor in folders in the sidebar of the Show All Bookmarks page). I had tried that, and have just tried again, confirming there is no contextual menu available.

Chris

Like many I have set routines for sites to visit over breakfast and so on. It's wonderfully convenient, and faster, to have a folder of the bookmarks I will want to visit at such a time that can be opened so that each bookmark is in a new tab. Most web browsers have a command in each bookmark menu and sub-menu to "Open All In Tabs" that allows this. The only way I have found in Opera 30 is to:
1.Show All Bookmarks
2.Select a folder (if it's a sub-folder I want I have to set the flags page for Bookmark organiser to show the full tree)
3. Select all bookmarks in that folder
4.Right click/Ctrl-click on the selected bookmarks and choose Open Selected in New Tabs.

It would be much easier to have a command in the menu. Perhaps I have missed a way to enable this? If not, I'm sure many users would appreciate it being available.

Chris