jq

 cat DBREP007post_2015_12_188.json | jq '.items | .[] | select(.ansatz >0) | .items | .[] | select(.ansatz >0) | .items | .[] | select( .zeilenart =="1" and .grp == "781") '

cat DBREP007pre_2015_12_188.json | jq '.Result |.FResList|."0" | .[] | select(.zeilenart=="4")'