So it seems you are filing nonresident returns for WI, GA & MI. Prepare those first in TT all the way to completion.
Then prepare your resident TT/CA return. TT/CA will "reach" into those completed nonresident returns to gather the information it needs to prepare the Other state tax credit for you. It needs the income taxed by those states that is also taxed by Calif, and the tax attributable to that income.
