This series returns from its winter hiatus with the primary focus not on the New Directions glee club, but on two of its graduates, now employed by a Broadway show preparing to open. One is Lea Michele’s Rachel, who has scored the lead role, once played by Barbra Streisand, in a revival of Funny Girl. And the other is Naya Rivera’s Santana, who has just been hired as Rachel’s understudy. All About Eve, anyone?