We want to offer a promotion for our customers where for every 3 products they purchase, they get a 10% discount. The promotion is specifically for 3 news products we're launching and every combination between these products is valid. For example:

• 1x Product A + 2x Product B
• 1x Product A + 1x Product B + 1x Product C
• 1x Product A + 2x Product B
• 3x Product A
• Etc.

So far, we've managed to achieve a calculated discount for the above through a promotional rule where the three products are selected as eligible with the amount set to '3'. In the checkout a new is created which calculates the discount correctly.

Now the main problem is: How can we multiply this discount rule in the checkout? For example: 

• 4x Product A + 2x Product B = 6 in total, so 2x the discount.
• 4x Product A + 2x Product B + 3x Product C = 9 in total, so 3x the discount
• 4x Product A + 1x Product B = 5 in total, so only 1x the discount
• 5x Product A + 5x Product C = 10 in total, so 3x the discount
• etc.

Our current solution is to just have multiple promotional rules that add the discount for every three eligible products that are added to the checkout, but this get's very messy, very fast.

Is there an option in Odoo 13 to multiply the discount for every 3 products that are added?

Hope someone can help me out or point me in the right direction. Thanks in advance!