How do I find the answer to this prompt: Enter the portion of these adjustments ($693 federal AGI) that applies to the time you resided outside DC?

Are you filing a DC part year resident return?  If so, this is asking how much of the deductions, credits or income applied to living outside of DC.  So, if you lived in Georgia for half the year and DC for the other half of the year, and earned half the money while living in GA, then you would enter $347 as applying to the time you resided outside of DC. The same would be for any expenses you entered as deductions.  If part of the expenses were incurred while a resident of another state, then you would enter the amount that you incurred while living in another state.