It's the method indicated the TurboTax help. The IRS is generally satisfied if the totals match up. Also, if there is no withholding in box 4, details of the Forms 1099-R are not included in your e-filing.
If these were independent distributions from a qualified retirement plan, any after-tax basis in box 5 must be split proportionately between the rollovers to the traditional and Roth IRAs. If these rollovers were the result of a split simultaneous distributions directly rolled over to two separate destinations following the guidelines of IRS Notice 2014-54, you would normally allocate the after-tax basis first to the rollover to the Roth IRA and any remaining after-tax basis (usually none) to the traditional IRA.
