There are 2 sollutions for this here: Multiple loops in the same Microsoft Word document?
I find the one with the json a bit complicated, the other one with the different the separators is good but it becomes more and more compicated and comsumes a lot of credits if you have more than 2 loops with a lot of bundles.
My sollution (at least I couldn’t find it anywhere): not using “Fill out a document with a batch of data” but the simple word template “Fill out a document”. I use an array aggregator after the bundles, and I set the target structure in the array aggregator for the word template modul as “loop or section”. Then in the word template modul I set the first values box to “Map” and map the merged arrays there.