CLion browsing in 3rd party CMake subprojects.

Greetings!

Please excuse dumb question, I think it is a well-known behavior at least. However, I wasn't able to find a clear solution or workaround for the last 10 minutes.

I have a project with CMakeLists.txt. 

It uses another CMakeLists.txt as add_subdirectory() - however, it is resided outside the file hierarchy of first CMakeLists.txt. 

My tiny problem is CLion can't browse (Shift-Shift) the source files for the second CMakeLists.txt project.

Is there a way to work around this?

I know if I will move 2nd project under 1st project root - the browsing starts to work. Is there another workaround? 

P.S.

Qt Creator does it without any problems.