*Just to preface this, I'm new to D&D Beyond and its Homebrew functionality, so I'm not entirely sure how it's supposed to work, and the information I found doesn't seem to answer my specific question.*

So, as the title says, is there a way? For instance, say I create a magic item that allows for multiple Breath Weapon uses for Dragonborn, but don't want to publish it. However, my friend is interested in it. Can I share it with him?

Or, if I'm the DM for a campaign, can I give this creation to one of my players who are part of my campaign here on D&D Beyond?

Or if I'm a player in another campaign, can I share it with my DM, so that I can have that item? 

If you and the person you want to share the item with are in a campaign together and that campaign has content sharing enabled, that person's character in that campaign (if any) can add that item. 

So, that means that a DM or the players can create magic items, and even if they're not publicly shared, they can be shared within the campaign, and utilized by all the members? That's really cool, I didn't realize it worked like that. I like that functionality. Now, would the players/DM be aware of the homebrew items, that they exist? Or would they have to search for them, potentially just stumbling across them if they're looking for a magic item to hand out? Or do they exist in their own separate Homebrew section for magic items?

You do have to stumble upon them. What I do is create a google spreadsheet of who made what and that's worked in the past.

Ah, okay. Thanks for the help, the idea of a google spreadsheet will help keep track of who made what.

I have been wondering this myself.  In my situation i am the DM of a campaign and  i have some private home-brew items and some public in my collection. i can add the public items onto my PC's sheet but not the private ones. 

My conclusion has been thus far, that private stays private; but a public item in a content shared collection can be added .

Is this how its supposed to work?