I am using version 8 platform update 15. Since the POS development is locked out and extensions only is allowed. There are some limitations and a number of objects are not accessible. I was trying to navigate to the customer search and allow the user to select a customer and return to the calling form. This was very challenging. One possible solution I found is to use Global variables. I used the window object. To do this, declare the window object as per screenshot. And then just set your object : eg. window.MyVarName = WhatEverObject; To get the value just invert it. You can see how I have the customer object in debug. Credit to one of my colleagues who suggested this solution.
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