I belive the following scenario is generic and other people will find it useful.
A mono repo contains git submodules. These submodules are separate git projects (by definition) with their own .circleci/config.yml files and can built/deployed independently. The host repository (monorepo) should be able to build each submodule as a part of its workflow by continuing with submodule projects circleci config files. It would be nice if we could specify which submodule branch to checkout.
My attempt
I found Path Filtering and Continuation Orbs can't handle the above scenario due to different reasons. My support request: 141996 confirmed the same.
Thank you!
Tharaka Manawardhana