For filtering param, This page demo-ed IN and CONTAIN,
https://developers.facebook.com/docs/marketing-api/insights/v2.4#filtering
curl -G \
-d "filtering=[{'field':'adgroup.delivery_info','operator':'IN','value':['archived']}]" \
-d "access_token=<ACCESS_TOKEN>" \
"https://graph.facebook.com/<API_VERSION>/act_<AD_ACCOUNT_ID>/insights"
curl -G \
-d "filtering=[{'field':'adcampaign.name','operator':'CONTAIN','value':'18-25'}]" \
-d "access_token=<ACCESS_TOKEN>" \
"https://graph.facebook.com/<API_VERSION>/act_<AD_ACCOUNT_ID>/insights"
But the information is very limited. Where can I find more info about the usage of filtering? e.g. How it should be if I want to filter out all items with blank (ad campaign) names? Or only the items with some attr (any type, e.g. dict or array) not empty (undefined).