What you are getting is a JSON structure. Each thing between {} is an object there. You can easily use an Import Mapping to map that to new objects.
https://docs.mendix.com/refguide/json-structures/
https://docs.mendix.com/refguide/import-mappings/
https://docs.mendix.com/refguide/import-mapping-action/
So if you purely want the assigned in “title” values, I would suggest to import “response attribute”-json with an import mapping action in a microflow. And then iterate over the list of objects and build a seperate string value that only holds the title values.