Often the quickest way to find input is to Check Return > Forms > All > locate the form you know where you want something to show up. On the Form often you will find shaded lines or boxes. Find what you want an click on it. 

In this case Form 1116 Schedule B list carry overs by year, you should pick the oldest and click on that line to start the input. That will take you to the GRID to do the carry overs. Next year, all of this will carry into the input, so you only need to do it once. 

Click on the top sections for type of income that generated the c/o

There is also this ARTICLE