I tested on VS Pro 2017 15.9.55, either with a newly created project(C#) or with a C# project but have some code added, the results are the same => only the functions of the currently active file are displayed. Everything was set by default as I tested with a newly installed VS 2017 and didn’t change any settings.
I notice that you are using 15.9.42, could you try to update it to the latest version of VS 2017? Besides, are you using any extensions which may affect the navigation bar? If you have set some configurations in VS, perhaps resetting VS settings(run
devenv /ResetSettings in VS Developer Command Prompt) works.
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