The difference between a Multipurpose Replication Group and a Replication Group for Data Collection is that:
Replication Group for Data Collection can be thought of as a hub with a single spoke. There is a “main” server that collects the data (consider it a repository) and the other server simply feeds the main server. If you want additional servers feeding data to the “main” server, then you need to set up additional Replication Groups For Data Collection. This is really for a special scenario setup of DFS Replication.
Multipurpose Replication Group is a more versatile setup and can operate in hub or mesh mode. If you’re not sure what to pick, pick a Multipurpose Replication Group.