Hi Sanjana,
there is no abbreviation to get the data out of the deep nested structure as shown in the document I referenced. Nevertheless this code works, so you should be able to use it (after adopting it to your specific structure of the decision table)
Concerning the download via the CL_FDT_DT_EXCEL. The method mentioned by Tee Gee might be an option. Nevertheless I would not modify it but copy the code to Z Namespace (both options are not optimal from a maintenance perspective but I would not go for a modification in such a quite central place of BRFplus). I also want to stress that you run into interesting results if you use expressions in cells of the decision table as shown in the screenshot below that you have to deal with somehow
Here another decision table is referenced in the first cell.
BR Christian