On the form 1040 schedule B. How I can change the 7a and 7b to YES?

You should go to:

1. Other Tax Situations
2. Scroll down to Other Tax Forms
3. Select Miscellaneous Tax Forms
4. Scroll and select Prepare a report on foreign financial assets
5. Now go through the questions

@JohnB5677 

TurboTax Online did not select 'Yes' on 1040 Schedule B Part III 7a after I answered the foreign bank account questions in Prepare a report on foreign financial assets. Likewise, 'Yes' was not selected after I answered questions in Wages and Income -> 1099-OID, Foreign Accounts.

As background, I earned $4k of interest from a foreign bank account with a balance over $10k but the balance was under the thresholds for Form 8938.  I reported the foreign interest income in 1040 Schedule B as I do for domestic banks.

As I understand it, I am required to select 'Yes' on Schedule B, Part III, 7a regarding having a foreign bank account. But I don't see a way to make TurboTax Online to do this in my situation.

The program asks every single person if they have a foreign bank account. That is one of the 2 most important questions in the eyes of the IRS. If you have denoted financial assets, you are done.

If you need to correct your answer or have not seen it:

1. go to Federal
2. go to Other Tax Situations
3. the questions may pop for you there
4. If not, go to Other Tax Forms
5. Select Show More
6. Select Prepare a report on foreign financial assets

I need to change schedule b part III from no to yes. I follow your steps. It still does not change that information on my tax form.

The best place to get to this section is to go:

1. to tax tools
2. tools
3. topic search
4. select foreign accounts and trusts, questions on Schedule B
5. The first question will ask Tell Us About Any Foreign Bank Accounts
6. If you need to uncheck an answer uncheck it. if it needs to be checked, check the right response and then fill in the remainder of the information it asks for. 

Your advice does give the desired result but I couldn't see this until I switched to the software version of TurboTax and used the forms view. As feedback I want you to know it was alarming to see TurboTax say

"Based on what you told us, it turns out you don't need to report your foreign financial assets." when it actually did select 'Yes' on 1040 Schedule B, 7a and 7b. It seems to be contradicting itself. May I suggest changing its choice of words to reduce the ambiguity and speak to the state of mind of more customers? Failure to report a foreign bank account can be a serious offense and some of us really want to follow the law but TurboTax is creating doubts, unintentionally I think, about its ability to help us do this. 

Thanks for advising on the process to change the Schedule B Part III 7a box between Yes and No. However I'm still not seeing a change take effect when I preview the tax forms. Any insight into why my selection in the Turbo Tax form doesn't translate to the IRS for for filing?

View>Forms worked for me! There is now a  NO on line 7a.