Database
[{suggest_foo:{foo1:"Foo1",foo2:"Foo2",foo3:"Foo3",foo4:"Foo4",foo5:"Foo5",}}]
Query
db.collection.aggregate([{$replaceRoot:{newRoot:{$arrayToObject:{$map:{input:{$objectToArray:"$suggest_foo"},in:{v:{$concat:["$$this.v"," maybe you like"]},k:"$$this.k"}}}}}}])