You can hide it from your account, but that will not hide your account from Threads.
A better option is to ask your server admin to block threads.net.
If you just want to hide it from your account, go to the profile of someone from threads.net, click ⋯ and then "block domain". But this will not really be a block as such if it's a user doing it.
Gregory's Server
@HereToChewGum @FediTips
Block Threads you mean?
You can hide it from your account, but that will not hide your account from Threads.
A better option is to ask your server admin to block threads.net.
If you just want to hide it from your account, go to the profile of someone from threads.net, click ⋯ and then "block domain". But this will not really be a block as such if it's a user doing it.