Storyline variables are exactly the same in masters and layers, it doesn't matter where you access a variable.

Thanks, I added the code to layers and its works. But I have one more challenge. I am not using google sheets as somewhere in this forum it was told that data cloud is much faster.

My challenge is whatever input my learners do, I prepare a dynamic chart and show the progress in their storyline file. How can I share the charts from the data cloud as a web object or if there is another way to export the data captured in the data cloud to some online sheets in real time?

I don't think there's a way to do this without a custom implementation. https://cluelabs.com/custom-development