You should be able to just use the output from the first time you created it, wherever that is, as your reference to its instance. You can store it as a variable and access at any time, via casting or whatever’s easiest.
Best practice would be to create it from the bp that will be interacting with it, so you can store the variable there. You can then use that variable to cast to the widget and perform whatever actions you need.
If that’s not option, when you create and store the variable, you can then cast to the bp that will be interacting with it and set a variable over there using your original variable containing the instance. Then you can handle all of your casting to/interacting with the widget from the bp that will be messing around with it.