The MakeAbsolute method takes a relative file name and makes it absolute. If the file is a content file, then the relative path is considered relative to the content project. If the file is a code file, then the relative path is considered relative to the code project.
Code Example
The following will obtain the absolute folder for the currently-selected element (Screen or Entity):
var currentElement = GlueState.Self.CurrentElement;
if(currentElement != null)
{
var elementNode = GlueState.Self.Find.ScreenTreeNode(screen);
var folderNode = elementNode.FilesTreeNode;
string relativePath = folderNode.GetRelativePath();
bool isContent = true;
string absolutePath = GlueCommands.Self.ProjectCommands.MakeAbsolute(
relativePath, isContent);
// do something with absolutePath here:
}