Mongo Playground

Configuration

[{anything:"whatever",something:{a:{getThis:"wow"},b:{getThis:"just wow"},c:{getThis:"another wow"}}}]

Query

db.collection.aggregate([{$addFields:{somethingArr:{$objectToArray:"$something"}}},{$match:{"somethingArr.v.getThis":"wow"}},{$project:{somethingArr:0}}])

Result