Hey there, razor518.
Good to see you here in the Community. I can provide some clarification on how your transaction would look like once it's downloaded.
After some thorough research, I found out that the full amount ($120) will show up when you download the transaction. Meanwhile, for details of the split ($50 and $70), they'll most likely be indicated in the Description field.
The same thing happens when you put in cash into your bank account. The full amount will still show in the For Review tab when you download the transactions. For additional insight about this, I recommend following this article: Get started with Bank Feeds for QuickBooks Desktop
Keep in touch if you have any other questions about this, or if there's anything else I can help you with. Have a great day!