Question on sharing Homebrew Items in Campaign

Is there a way to share only the homebrew items that I have created with the players in a campaign I am running instead of sharing all homebrew creations?

Only things that are in your "My Homebrew Collection" will be shared in campaigns. If you've created something that you don't want to share, you can remove it from your collection and then it won't be shared. (It'll still show up for you in "My Homebrew Creations".)

However, if you are in multiple campaigns, there's no way to pick and choose which things are shared with which campaigns. It's all or nothing.