What is subject in you language?
In C::B's terms we use 'project'.
What I've ment was:
1. Create a project
2. Create two targets
3. Add the first file to target1
4. Add the second file to target2
5. Build target1 or target2
6. Add virtual target to combine the two targets, so they get built together...
The same can be done with two separate projects...