In TurboTax Desktop Premier, I am able to enter Nondeductible expenses in the Stock and Debt Basis Limitations Smart Worksheet line B.
In Part I Shareholder Stock Basis, make sure that a value is included in line 1 Stock basis at the beginning of the corporation's tax year and/or line 2 Basis from any capital contributions made or additional stock acquired during the year.
The entry on line 8a Nondeductible expenses does not seem to appear unless there is a value entered on line 1 or line 2 above.