I'd like to have a way of enabling only Homebrews in my collection. Such that if a DM wants to require a Homebrew I'll add it to my collection cautiously and then have the power to remove it from my collection when no longer required.

I have players that play in other DMs campaigns, those other DMs have homebrews that are not compatible with my campaign.
My players are now stuck with a list of homebrews from all their DMs that they have to wade through, with the current solution being to select the feat or subclass Homebrew and then deactivate Homebrew for the character.
I also play in other DMs campaigns and I want to distinguish which Homebrews are from who, I know homebrews from certain people are untested and unbalanced train wrecks.

Homebrew need not be in your collection to use it. If we are in a campaign together I can add something from your collection to my PC without ever adding itl my own collection at all.

Alternatively, if you have something in your collection and add it to a character sheet, you can then remove it from your collection and it will still remain on that character, fully functional.

I hope that helps.

Not exactly, I actually want to not have things automatically shared with me.
I'd like a function/method in which I can ignore Homebrew that I have not manually added to my collection.
There is a lot of Homebrew and whilst my friends, most of the time my friends make terrible Homebrew that I'd like to not have in my more serious tone campaign.

For example, imagine this scenario:

My player has Homebrew from another DMs campaign, however, the character they are currently playing with is in my campaign. 
They get a level and want to take a Feat, they and I need to wade through the Homebrew feats of every DM they have a character with, even ones they never use, whilst trying to find my Homebrew for the campaign actually relevant to the character. 
I run D&D reasonably close to the base rules and apply my knowledge of the lore and FR setting. Other DMs will have joke Homebrew with guns, candy cane weapons, and the ability to summon Elvis Presley Aarackocra - that is not the tone of my campaign and many are less obvious than that.

My point was that neither of you should have to wade through all of those homebrews. That player should be able to add that homebrew to the character in the other DM’s campaign without ever adding it to their own collection. In the totally separate campaign they are in with you that homebrew should not even be visible.

Don’t get me wrong, I too (along with everyone else) wants more granular controll over the sharing of homebrew in their campaigns. I’m just letting you know that those players don’t really have to add that 💩 to their collections at all, and if they remove those homebrews from their collections it will solve your problem without ever adversely affecting their characters in those other campaigns.

Cool, just raising the awareness of that desire for more control over shared homebrew was the reason for my post.

Just trying to help you ameliorate your issues as best as currently possible was the reason for mine.

Quote from Andrak_Sanguine >>

Cool, just raising the awareness of that desire for more control over shared homebrew was the reason for my post.

 They know we aren't subtle about it. I for one want to be able to sort my collection into sourcebook-like folders that can be toggled on and off as a group (along with other source books since that isn't a thing yet either for some reason).

But your specific problem shouldn't exist unless the other DMs are players in your campaign or your players are unnecessarily adding copies of other DM's homebrew to their own collections.

Aye, the other DMs do play in my campaigns.

Quote from Andrak_Sanguine >>

Aye, the other DMs do play in my campaigns.

 Ok then, that is why it's happening.

Yeah, they need to fix this. Especially since homebrew is not labeled on the character sheet, let alone who's homebrew it is.

In a shared campaign, if I understand things correctly, any homebrew added to anyone's Homebrew Collection -- including any fellow DMs' homebrew that also play as player in your campaign -- will be shared and usable. You could try to find out who among your fellow DMs or players have added stuff and ask them to remove it from their Collection, but this gets a bit crazy when you have multiple campaigns with a lot of different players. Also, they might not want to remove a particular homebrew they found in the D&D Beyond homebrew section because one of their characters (or a character in another campaign) is using it, or they simply want to find it for later reference.

There is a need for more granular control. In a shared campaign, we need toggles (ON/OFF) for shared homebrew content from each player in that campaign.