Database
[{"aField":1,"otherField":2,"likedBy":["id-1","id-2","id-3",]},{"aField":1,"otherField":2,"likedBy":["id-2","id-3",]}]
Query
db.collection.aggregate([{$match:{"likedBy":"id-2"}},{$project:{likedBy:{$filter:{input:"$likedBy",as:"likedBy",cond:{$eq:["$$likedBy","id-2"]}}},aField:1,otherField:1}}])