Can I travel to Macedonia and Albania on Schengen visa? Do I need transit visa for Germany if my stay is less than 4 hours within the airport?

According to the information provided in the comments, your plan is to visit Greece, Albania, and Macedonia on a single trip.

While a multi-entree type C Schengen visa seems to be sufficient for entry into Albania and Macedonia, note that this is a special case. Macedonia and Albania are independent from the Schengen area, and it is thus their choice whom they let and in whom they don't. The rule that travelers with a Schengen visa can enter without visa is just to make their life easier by assumiing that if a traveller is "trusted enough" for a multiple-entry Schengen visa, this seems to be good enough for them.

Yet, it is very unlikely that a Schengen state embassy will issue a visa for the purpose of visiting a non-Schengen state. You could always apply for a Macedonian and Albanian visa separately.

There is the remote chance that the Greek embassy (whom you would address your application to as Greece is the primary destination of your planned trip in the Schengen area) will issue a multiple-entry type C visa that is valid long enough anyway. You could apply for what you want, provide a correct itinery, and explain why you want you visa to be valid for at least 5 days after all of these countries have been visited. If you are in luck and the visa officer doesn't see a problem with that, you may get what you asked for. Especially if you are a first-time applicant for a Schengen visa, I wouldn't bet on this to work, however. After all, it is not the task of the Greek visa officer to decide who is allowed to enter Macedonia or Albania. So be prepared for making seperate applications for Macedonia and Albania.

Of course you can travel in Albania and Macedonia with Schengen Visa. Enjoy your trip.