Open .sln in VS2013 which has files in different VCS repositories

Question

I had a working native solution in one repository. Now, I have a use case where my other project also uses the same files. So, I have a few files in one repository(git) and solution file and other few files in another repository(hg). Now, when I clone those two repositories in my system and open the solution, I want it to include the missing files from other cloned project or other directory so that the solution opens successfully. Kindly help me.