There is no easy answer to this question, as using chicken broth instead of the concentrate may rely on the recipe you are using.  In general, chicken broth is a less concentrated form of flavor than chicken concentrate, so you may need to use more of it to get the same flavor in your dish.  However, chicken broth can also be used in place of concentrate to dilute the saltiness or "tinny" flavor that you might get from using all concentrate. If you're trying to replace a bouillon cube with a less concentrated form, 1/2 cup of the chicken broth should roughly replace 1 cube. The chicken concentrate is usually used to add flavor to dishes. Still, it can also be used as a marinade base or as the liquid in which you cook certain ingredients.  Chicken broth can also be used as a marinade base. Still, it's generally not used to flavor ingredients that are cooked in it, as they will release some of their own flavors into the liquid.