You can use the microflow option for that. In the microflow you can define your own retrieve action. The only thing is that you have to add a searchfield to your entity in order to get the searchvalue into the microflow. (Or you can use a non-persistent object wrapped around it of course).
You could create an attribute wich is made from the 2 attributes you need the search on. Like:
Attribute1-attribute2
You can fill that New attribute in a before commit and then set that attribute to search on