How to use VS2015 debugger to analyse one function called by a unit test, whilst running previous tests?

I have a series of C++ unit tests programmed in Visual Studio 2015. The last test calls a subroutine which is hanging. This subroutine, uses global variable defined during function calls in previous tests. Hence, I need all tests to run, however, I would then like to use the debugger only of this list test to analyse why the final function is hanging. I can't right click -> debug selected test, as it only runs that test. Can, and if so how do I do this?