how do i consolidate all x unit projects under a single folder in order to add the o one single source control?

i am using visual studio 2019 to create simple asp.net 2.1 mvc project. i have added two more xunit projects in the same solution as the mvc project, however i want to add all these projects to a single source control such as github. so when i try to add a source control it gives me the following caution: "the current solution has project that are located outside of the solution folder. these project will not be source controlled in a git repository." my question is how do i get to consolidate all the project under a single folder and the solution does not break