[{"_id":"123","details":[{"_id":"1","address":"Ramat Gan","cost":"50"},{"_id":"2","address":"Tel Aviv","cost":"30"}]},{"_id":"456","details":[{"_id":"4","address":"Modi'in","cost":"40"},{"_id":"5","address":"Tel Aviv","cost":"20"}]}]

db.collection.aggregate([{$project:{top:{$filter:{input:"$details",as:"item",cond:{$eq:["$$item.address","Tel Aviv"]}}},bottom:{$filter:{input:"$details",as:"item",cond:{$ne:["$$item.address","Tel Aviv"]}}}}},{$project:{details:{$concatArrays:["$top","$bottom"]}}}])