How to make form always on top in Application

How to make form always on top in Application

I have a form that i want to always be on top whenever it is opened in the
application but i dont want it to be on top when the main form is
minimized or another application is navigated. I want it to be on top only
in my application.
Following the answer in the question : How to make a window always stay on
top in .Net?
this.TopMost = true;
Makes the form on top but the form is still on top when another
application is navigated to or the main form is closed.
Pls how do i make the form only on top in the application while enabling
user to still work on the main form?