you should ideally automate this. I believe you have a Qlikview server. If so you can use QMC to schedule refresh tasks.
If you don't have a server, you can simply automate the qlikview refresh using the Windows Task scheduler or any scheduler. Create 3 batch files one for each layer with the following command. You wouldn't need user to click any buttons.
But I still wonder... What if the user don't want to wait until the task is executed automatically... is it anyway to "force" the execution of the load QVWs from Inside qlikview (The "Button")? (Server or Client)
I know I could create a batch file with the same commands that I should use for Tasks.. but that's horrible for the User Interface...