By clicking the 'Save' button the current report will be saved automatically to the current path in the explorer. Please note that once saved a report can only be opened in read only mode and the design cannot be changed.
The Explorer is visible on the left of the window:-
You can navigate to the directory of choice to save the reports in.
Use the right click to expose to control menu to navigate or Alt+2 to go up a level.
Other useful options are the ability to set the current path as the root:
Or to navigate the directory/network to set the default root for report saving, this selection is saved on exiting.see Setting up Multiple clients
Reports are saved automatically generating a sequential file name 'NewReport..' This can be changed by clicking into the file name in the explorer