You would have to do this manually for each group of payments as they come due, or set up a second account.
From this support article --> How apps, content, and subscriptions from Apple are billed - Apple Support
"Which payment method is charged?
When you buy items or pay for subscriptions, Apple automatically attempts to charge your payment methods in this order:
1. Apple attempts to use your Apple ID balance to cover the full amount.
2. If you don't have Apple ID balance, you don't have enough to cover the full amount, or an item cannot be paid for with Apple ID balance, Apple attempts to charge your primary payment method (typically a credit or debit card, but varies according to country). The primary payment method is at the top of the list in Settings on your iPhone. You can control which payment method is at the top of the list. [See: Add a payment method to your Apple ID - Apple Support ]
3. If there's a problem with the primary payment method, or if the primary payment method can't be charged for the full remaining amount, Apple attempts to charge your other payment methods in order from top to bottom. If none of them can be charged, Apple may try again."
Here's how to change the payment method order for your Apple account after Apple account balance (which will be charged first in all cases unless the item you are buying cannot be charged to account balance). For the first four steps, refer to the first image in this Support article Add a payment method to your Apple ID - Apple Support where it says to tap Edit to reorder or remove a payment method.
1. Tap on the Settings app.
2. Tap on the Apple ID section at the top of the page.
3. Tap on iTunes & App Store.
4. Tap Edit.
5. Tap and hold on your preferred Card and drag it to the top.
6. Tap Done.
Another method would be to set up a second Apple account/ID with one group of purchases being bought on that account with its own payment method. Then use Family Sharing to share the purchases with the other ID. To learn how to set up Family Sharing, read this support article --> Set up Family Sharing - Apple Support
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If this end up being a duplicate then I apologize. Apple's forum interface sometimes does that when I try to edit a post.