How can we do submenu and show on the bottom how i can send back to main menu
Welcome to the forum.
Please become accustomed to provide decent context info of your problem.
It is always helpful to carefully and detailedly phrase a request, and to support it with system info like OS and shell, related environment (variables, options), preferred tools, adequate (representative) sample input and desired output data and the logics connecting the two, and, if existent, system (error) messages verbatim, to avoid ambiguities and keep people from guessing.