I would like to visualize the difference between the current timestep and the previous one, so it demonstrate the hourly value, not the total accumulation
You can use the Temporal Shift Scale filter to get a copy of the data set at a different timestep. Both the data from the original reader and the data from the temporal shift will be available in the pipeline, so you can use them together.
I’m not sure what you mean by “visualize the difference,” but perhaps you want to use Append Attributes and then the Calculator filter to take the difference of the same field from the two different datasets (i.e. datasets from different times).
After using your way it came to my mind to do it in the following manner:
Use the TemporalArrayOperator on the dataset with the variable used
Add a track in the AnimationView with the properties First Time Step Index and Second Time Step Index of the TemporalArrayOperator one going from [1, maxtime] and [0, maxtime-1]