TFS 2013 Build Definition has an Output Location option (AsConfigured, PerProject, SingleFolder) but this option is not available in the later version.
TFS 2013 is XAML based build definition, later versions new build definitions are added like vNext/YML. So in TFS 2015 or later versions if we use vNext/YML build definition this option is no longer available so we should have use alternate options in build template to set output location. By default, it is “As Configured”, to build to a single folder we can pass /p:OutputPath=$(Build.BinariesDirectory) as build arguments, which will drop all the output in a \b folder next to \s (sources).
To build each solution to a separate project, we need to add multiple Visual Studio tasks and configure each to have /p:OutputPath=$(Build.BinariesDirectory)\SolutionName or create a task “Copy Files to: $(build.artifactstagingdirectory)” which copies files to \a folder next to \s in Agent_work folder.
TFS 2015 or later versions still support XAML build too, so we can still use this Output Location option in TFS 2015/Azure DevOps XAML build definition.