When you insert a data function as transformation, I don't see how you can find out where it is loaded from, so if you have stored a data function with the same name multiple times, you cannot find out which one is actually used in the transformation (at least I don't know how). It would be good to see the guid of the data function in the source information of the data table to easily identify it.
The Library identifier of the Data Function is visible in the Source View details and in Data table properties.