You'd need to go to the input screen for the activity for which §179 was disallowed.  For example, for Sch C, you'd use Screen 16, scroll down to the Depreciation, Depletion, & Amortization section, and enter the amount for Section 179 carryover (and for AMT, if different).  For Sch E, you'd use Screen 18 and scroll down to the Depreciation, Depletion, & Amortization section.  You get the idea...