So what do you mean like this, do i have to collect all the items and then do something? and the answer to that is sort of no.
There is an easier solution if you already have one that’s discovered or have gone to worlds before 1.7
Now to do it its pretty simple.
Buy the item of choice to discover and buy a few chests if you are looking to make more then 1 item discovered.
Note: you only need one of each
And then when you are ready you can transport them via portal chest to the chosen world.
Then take the chests out of the portal chest and look inside the chest
Then get out and look at the trade portal. you’ll see all the items you have chosen discovered.
I hope this helps some out on their journey
This is only for vanilla because custom doesn’t have portal chests but still, i hope it helped some of you out