Thanks for the feedback, Aleksandr, and I’m sorry for late reply. There is an example in this blog where Product is another POJO in FoodSampleDTO POJO. If you meant combining two POJOs then yes, you can write a mapper with two POJOs as input (I used that to solve a problem where I already had an instance of POJO created which I needed to further fill in using a mapping, so I passed the pre-created POJO instance and another POJO to get a new version of the pre-created POJO filled with values from the second POJO).
I’d suggest you take a look at great documentation and examples. Also, there are other mapping frameworks that you may want to check out (ModelMapper is another good one).