mongodb - one document in many collections

mongodb - one document in many collections

i'am looking for a good solution on MongoDB for this problem: There are
some Category's and every Category has X items. But some items can be in
in "many" Category's!
I was looking for something like a symbolic link on Unix systems but i
could't not find it.
What i thought is a good idea is: "Category1/item1" is the Object and
"category2/item44232" is only a reference to "item1" so when i change
"item1" it also changes "item44232".
I looked into the MongoDB Data models documentation but there is no real
solution for this.
Thank you for your response !