The closest comparison I can think of is the Add option when using Pathfinder in InDesign and Illustrator. If I build a new object made up of multiple objects, I know I can group it together. But is there a way to finalize that part so its one single unique object that can not be taken back apart?
Hello, with Dimension it's impossible to do that. Maybe in the next versions.
Yopu can group objects to have all in one place. You can also try the magic wand tool to select part of objects to assign material or delete it.
But a tool like the pathfinder in Dimension would be awesome!