How to do a merge for a hotfix in TFS within Visual Studio 2017.

1. Pull down to a different folder the folder to merge to from the SAME workspace. Do not change workspaces.
2. In the "Source Code Explorer" right-click on the folder containing the stuff you want to merge in and pick "Branching and Merging" and then "Merge..."
3. Walk through the little wizard. Click the "Selected changesets" radio button. The "Source branch:" setting should be mapped to the stuff you want to merge in and the "Target branch:" should be mapped to where you want to merge to.
4. The next page of the wizard will let you cherry pick what you want to merge.