You can merge:
Changes across streams or their folders.
Changes from a baseline into a target stream.
Changes from requests owned by another stream into a target stream.
Merge is similar to Update and uses a work area to apply changes and process conflicts. This enables you to safely merge, build, and test before delivering the merge results to a target stream in a repository.
When you merge two objects, for example a stream with another stream, or a stream with a baseline, Dimensions CM looks for a common ancestor. This is a point in time where the streams or work areas diverged. This is typically referred to as a three-way merge. For example, assume you have two streams that were created from the same baseline. Modifications are performed in both streams by different developers and delivered to CM. You now merge stream 1 into stream 2. Dimensions CM looks at the baseline (the common ancestor), finds the modifications that were delivered to stream 1 after that point, and merges those changes in stream 2.
The merge process uses changesets to find the common ancestor. A changeset is a logical grouping of changes that is created automatically every time that you deliver changes to a stream or project in a repository. For details see Working with Changesets.
For merge examples and use cases see the chapter Merging Changes across Streams in the Dimensions CM User’s Guide.