There are some ways to split transactions. It usually depends on some specific detail of the use case, such as tax recording or simply split an expense.
That is similar to an Accounts Payable or Credit Card flow, so, you can think of the intermediary account as your supplier, such as "Supermarket", so, you could do that the original way you thought, but, instead of give a generic name "SPLIT" you could give a meaningful name for that account, such as "Supermarket". So, you first buy things:
That will generate a $30 outstanding balance, then you pay:
If you pay the whole amount, it will clear the outstanding balance, but you could pay in installments, so, instead of give the $30 payment at once, you could, for example, pay in 3 installments of $10, and keep track of the outstanding balance as you go.