It's in the Design and Reference Guide. In addition, you have OneStream Academy if you have access to it. If you have been to the OneStream training, then I think you should have access.
Hello BP, there might not be a totally separate content on it, since this is an overall understanding and functionality. If you can help with your questions, we should be able to answer this:
Few points:
1) Entities do not aggregate at their own (Dynamic) until you the right percentages (100 to start with) in relationship tab and you execute Consolidation at a parent entity.
2) Functional name of Entity aggregation (For finance) is 'Consolidation'
3) You can use a dynamic aggregation of entities with different currencies using UD8 dimensions with a specific Dynamic function, in this scenarion system disregard any custom translation rules and follows scenarion rates to run the translation and aggregation.