How to create a menu block which is created by the active trail I'm trying to create a sidebar block which contains secondary and tertiary menu links for a page which is in the main menu. I would also like to ensure that all children pages also have this same menu block.

I have been looking into the Menu Block module, but I don't think it will work for my situation. It looks like that module shows a subset of a particular menu, but it doesn't change per page. I don't want to create multiple menu blocks, just use one and have it change dynamically.

Is there a solution in the community for this?
Menu Block does cover your use case.

Go to /admin/config/user-interface/menu-block

You will see


  If a block is configured to use "the menu selected by the page", the block will be generated from the first "available" menu that contains a link to the page.


That screen is for administering which menus are available when the menu block is supposed to simply rely on the active trail to determine which menu to show.