I think I found a workaround that I thought I would share in case it is helpful to others.
On the "Other States" dropdown menu, the first option is blank. Choose that option and complete for the relevant state (let's say AZ). Then, click the "Show Relevant Form" arrow in the lower left corner. After that, go into the body of the form and chose AZ from the dropdown menu in Item A of the worksheet embedded in Part II of the form -- for some reason, AZ is available on this dropdown menu but not in the "Other States" dropdown menu in the main interview. This will enable you to create a Schedule S for AZ and the entries will be included along with Schedule S entries for other states to calculate your aggregate state tax credit.
The only hitch is that after you are done with your return and perform an error review TurboTax will flag this as an error on the basis that a California resident cannot claim an other tax credit for AZ (which is true for an individual but not if you are claiming through a partnership that paid AZ tax on a group return). I plan to ignore this error and proceed to file.
