How can join dynamic collection in mongodb

Question

I need to join with a collection that is selected from the field

collection: master

_id	collection	refId
M101	related_a	A101
M102	related_b	B101

collection: related_a

_id	Name
A101	A-111
A102	A-222

collection: related_b

_id	Name
B101	B-111
B102	B-222

Expected Output

_id	collection	relatedItem
M101	related_a	{refId:A101, name:A-111}
M102	related_b	{refId:B101, name:B-111}

db.master.aggregate([
{
   $lookup: {
       from: ,// Base on collection field value
       localField: 'refId',
       foreignField: '_id',
       as: 'relatedItem'
   }
}
]);