Call a script in the other file.
Operating 2 similar databases is probably not the best choice.
To call a script in the other file, use the perform script step and specify the script in the other file.
After adding this step: Click specify. Select "Add filemaker data source" to open a dialog where you can select the second file. Then you'll get a list of scripts in the other file and you can select the one you want to perform to switch the user to the desired layout.