Subtrees
Subtrees allow to integrate contents from other repositories into sub-folders of your main repository. They are an alternative to Submodules.
Subtrees in the UI
Refs belonging to subtrees will be denoted in the Branches view by a folder-symbol. The root commits of a subtree will be denoted the same way in the Log Graph.
Subtree operations
To add a new subtree, select the root directory of the repository in the Repositories view and invoke Remote|Subtree|Add.
To merge (or cherry-pick) a subtree use the Merge (or Cherry-Pick) command. SmartGit will understand whether the source commit is a subtree and in this case perform a subtree merge (or cherry-pick).
To split changes from your main repository back to a subtree, first Check Out the branch which should be split back. Then, in the Branches view, select the subtree branch to which the changes should be split back and invoke Subtree|Split from the context menu. Note that SmartGit will not actually split changes back to this particular branch but the branch selection serves primarily to identify to which subtree the changes should be split back. The underlying Git command will then detect the appropriate subtree commits onto which the new commits will be split back.
To reset your main repository to a certain subtree, first Check Out the branch which should be reset. Then, in the Branches view, select the subtree branch to which your main repository should be reset to and invoke Subtree|Reset from the context menu.