SubstreamPartitionRouter to iterate over a list field of parent

[mario-nieto-perez]

Hello guys,
I'm trying to use the Low-Code API to build a connector for an API. So far I've been having great results, but now I found a situation where I don't know the best way to proceed.

I have to iterate over some record using the SubstreamPartitionRouter, but the field is inside a list of record, an example of one of the parent record is like this:

{
  'id': 123,
  'reports': [
    {'year': 1999, 'url': '/123/reports/1999'}, 
    {'year': 2000, 'url': '/123/reports/2000'},
    ...
  ]
}

I need to access the year field inside each of the elements of that list, but the SubstreamPartitionRouter only allows for strings, so I cannot use it directly. I was thinking about probably needing to build a custom PartitionRouter, but I don't know if there is any alternative easier.