Subsetting OLCI l1 Data

Hi, I am trying to subset level 1 OLCI data to make future processing faster. I have 1,098 .SEN3 folders containing multiple .nc files. How do I subset all .nc files in each folder to the polygon I want? I’ve tried subsetting the .xml file, but the new products are saving as .nc.dim files?

You can use the Subset option within the GPT for batch processing using a polygon as input.
For batch processing using SNAP, there are some examples here: Subsetting several S2 Images