We ended up writing a custom promotion for that, following the guide:

https://world.episerver.com/documentation/developer-guides/commerce/marketing/custom-promotions/

Look into the implementation for the default "Spend for free items" promotion and any promotion that has a selection for inspiration.

Thanks, Erik Norberg,

I implemented a custom promotion. But how can I pass "Limit number of discounted items" value to Promotion Engine? and how to pass dynamic values to "Limit number of discounted items"?

I don't follow you, what value is that?

Can you share the code of your implementation?

Thanks for your reply.

I use the below code.

protected override RewardDescription Evaluate(EntryPromotion promotionData, PromotionProcessorContext context)
        {
            var lineItems = GetLineItems(context.OrderForm);
           
            var condition = promotionData.Condition;
            int requiredQuantity = condition.RequiredQuantity;
           
            var applicableCodes = targetEvaluator.GetApplicableCodes(lineItems, condition.Targets, condition.MatchRecursive);

           
            //// filter the lineitems based on the required quantity(line item qty should be equal or greater than required quantity).
            var filteredLineItems = GetFilteredLineItems(lineItems, requiredQuantity, condition.MixMatch);

            //// filter the applicable codes based on the filtered lineitems.
            var filteredApplicableCodes = GetFilteredApplicableCodes(applicableCodes, filteredLineItems);
           

            var fulfillmentStatus = fulfillmentEvaluator.GetStatusForBuyQuantityPromotion(
            filteredApplicableCodes,
            filteredLineItems,
            requiredQuantity,
            minRequiredQuantity
            );           

            return RewardDescription.CreatePercentageReward(
                fulfillmentStatus,
                GetRedemptions(filteredApplicableCodes, promotionData, context, lineItems),
                promotionData,
                promotionData.Percentage,
                fulfillmentStatus.GetRewardDescriptionText(localizationService));
        }

I need   

" Buy Products for Discount from Other Selection
Buy at least X items from catalog entries and get related catalog entries at a discount." promotion.

If user buy A,B,C (3) products,we should apply 10% discount for Product D.If I use this default its working fine.But How can I pass "(Limit number of discounted items)MaxQty" in Evaluate method.Is there any possiblity?

kindly help.

Is this a new promotion and no longer the give away from your original post?

For give aways your processor should inherit form the GetFreeItemsProcessorBase

public class YourCustomPromotionProcessor : GetFreeItemsProcessorBase<YourCustomPromotionData>

What does your PromotionData look like?

Than you.

I used EntryPromotionProcessorBase.

MyEntryPromotionProcessor : EntryPromotionProcessorBase<MyEntryPromotion>

Can you explain me the Evaluate() method for  GetFreeItemsProcessorBase?.How can I achieve this?

Decompiling the source code for GetFreeItemsProcessorBase gives you:

	protected override RewardDescription Evaluate(TEntryPromotion promotionData, PromotionProcessorContext context)
	{
		PurchaseQuantity purchaseQuantity = _conditionGetter(promotionData);
		IList<string> applicableCodes;
		FulfillmentStatus fulfillmentStatus = purchaseQuantity.GetFulfillmentStatus(context.OrderForm, _targetEvaluator, _fulfillmentEvaluator, out applicableCodes);
		if (!fulfillmentStatus.HasFlag(FulfillmentStatus.Fulfilled))
		{
			return NotFulfilledRewardDescription(promotionData, context, fulfillmentStatus);
		}
		context.AddConditionalItems(promotionData.get_ContentLink(), applicableCodes, purchaseQuantity.RequiredQuantity);
		IEnumerable<RedemptionDescription> redemptions = GetRedemptions(promotionData, context, applicableCodes);
		return RewardDescription.CreateFreeItemReward(fulfillmentStatus, redemptions, promotionData, fulfillmentStatus.GetRewardDescriptionText(_localizationService));
	}

Of course you have to replace the PurchaseQuantity condition with your own one to support your use cases.

Thanks..Its working fine.

But,For example if I add 5 products to cart and i give purchaseQuantity.RequiredQuantity as 1,discount will  apply for only one  product.But it applied to 5 products.