There currently isn't an automated way to combine 2 different products together. However, it's still possible to do as long as they are from either Aliexpress/eBay sites.
1. You would first need to import one of the products and then send it to your store using Dropified chrome extension.
2. Then, you will edit the product in your store admin and add the new variants of the next product one by one. Make sure to save the changes from your store admin so it will sync to Dropified.
3. Add the second product as an additional Supplier to the first product from connections tab of your Dropified account.
4. Once you've done that, you can use the Advanced Variant Mapping to connect each variant to its proper AliExpress/eBay product page so that Dropified will know which product to order when you place the order.
Note: You will have to go to the Addon store section to have Advanced Variant Mapping tool installed to your account.
You can watch the video demo below to show you how Advanced Variant Mapping works: