How does github action will work with dotnetcore multi project and visual studio solution?

[amepani]

How does GitHub action will work with dotnetcore multi project and solution?

I am having difficulties for configuring dotnetcore multi project visual studio solution with GitHub Action with environment variable for project path.

Note : Solution is not at root location but it is inside SourceCode Folder.

MSBUILD : error MSB1003: Specify a project or solution file. The current working directory does not contain a project or solution file.
##[error]Process completed with exit code 1.
##[error]Deployment Failed with Error: Error: No package found with specified pattern: SourceCode/SubProject/myapp

If you provide sample application for this type of Visual studio solution it is very useful.