Llvm-cov: how to fold parts of a coverage summary by subdirectory?

Hi all,

Does llvm-cov support folding parts of a coverage summary by subdirectory in html format? My users have lots of test cases in different directories, and llvm-cov lists all cases in one html with no folding. What I want is that llvm-cov can show these cases folded by their subdirectories, like gcov/lcov way. An example of comparison llvm-cov and gcov/lcov is here.

Llvm-cov: http://lab.llvm.org:8080/coverage/coverage-reports/llvm/index.html

Gcov/lcov: http://llvm.org/reports/coverage/

I see similar requirements in http://lists.llvm.org/pipermail/llvm-dev/2017-October/118428.html but not sure whether this feature has been achieved. Is there any patch or script for this requirement?