Not sure if you are asking about Form 1116, but if so I have the same issue. I think this is relevant from the IRS instructions:
>>>Line 3b. Enter on line 3b any other deductions that don't definitely relate to any specific type of income (for example, the deduction for alimony paid from Schedule 1 (Form 1040), line 31a).<<<
For me this was an IRA contribution and self-employment tax. Not tied to any particular geography, so the form lets you use a share of them here.
