[Now solved … see below … using Krusader as staging post]
There are a few earlier posts on this subject. There is a neat feature where I right click on Editor window and choose … Open Containing Folder
Now this opens in the default file manager, in my case in Ubuntu it is Krusader … which is handy since Krusader has its own powerful ecosystem for post processing Subl content.
But there are occasions where I require to open the file in focus in a different default file manager or IDE. An example might be Thunar or DoubleCommander to be compatible with another party sharing workflow.
So when right clicking and Open Containing Folder … how to offer options from an associated list of file managers?
Example DoubleCommander which (unlike Krusader) is cross platform? Or even an exotic app such as Meld?
I can do this using Open Terminal Here then typing an external command. But it would be cleaner in subl menu.
SOLVED: I am staying with Krusader since from Krusader I can launch the target Subl text file in many directions …