Are there any restrictions to filters?

Hello Nick, 

On this case, it seems that you are trying to filter from a related field on Teams module, so you can try specifying link and the field name: "teams.id" for example:

{
   "filter":[
      {
         "$and":[
            {
               "id":"012693e0-711a-11eb-9442-023123a8c872"
            },
            {
             "teams.id":"1"
            }
         ]
      }
   ]
}

Can you check if this works for you?

I will try that. I was just using what came in that field in the response to the GET without wanting to get involved with the links between modules. I think you have gven me enough information. Thanks.

to extend this, if i filter Documents with {"filter": [{"related_doc_rev_number": {"$equals": "1"}}] i get "error_message":"Invalid link documents for owner clause" is it safe to join on relate