Resolve Conflict: Compare "Theirs" with Base, Compare "Mine" with Base.
In the Resolve conflict dialog, when you right-click on a file, please add the following to the context menu:
Compare Mine with Base Compare Theirs with Base
Similar to "Compare with base", this feature opens TortoiseGitMerge and shows differences from only one branch against the common base.
The files necessary are already available as either (Myfile.BASE vs MyFile.LOCAL) or (MyFile.BASE vs MyFile.REMOTE).
This makes it easier to visualize the changes made to each branch independently as of their common base.
I find that with the three way merge display in TortoiseGitMerge it can be difficult to visualize what the intent of the changes were in one branch vs the other when they are interleaved. These two new options allow those changes to be viewed separately as a visual diff.