@bbsin
I am not clear on what you are asking, but if you want to have a Gallery and a form on the same screen, then this is just a design consideration...place them both on the screen if wanted.
Your formula seems to indicate that you Navigate to Form1. Unless the screen you're navigating to is called Form1, then this will not work. Navigate takes you to a new screen by its name. You do not specify a control (i.e. the Form) as where you want to navigate.
Beyond that, I am not clear on what is form and what is gallery in your picture. Even though labeled, the concept you have there is not making sense.
I hope this is helpful for you.
