When reporting the details about each foreign account or asset, you will need to report whether it is owned jointly with your spouse. However, it does not ask for the name of other joint owners or if you have any other joint owners.
In the instructions for Form 8938, each joint owner (if not your spouse) must include the entire value of the jointly owned asset to determine the total value of all of that joint owner's specified foreign financial assets.
Example from instructions: I am not married and do not live abroad. An unrelated U.S. resident and I jointly own a specified foreign financial asset valued at $60,000. You each have to file Form 8938. You each satisfy the reporting threshold of more than $50,000 on the last day of the tax year.
https://www.irs.gov/pub/irs-pdf/i8938.pdf
https://www.irs.gov/pub/irs-pdf/f8938.pdf