For example, if you're in a party but not the leader, instead of "Invite to Party" as an option in the menu, you'll be able to click "Recommend for Party" which will bring the suggestion up to the party leader.

If you're trying to invite someone who is already in a party, it will instead ask the leader of their party if you can join.

They can have the option to block these, if folks would prefer not to see them (and/or have a cooldown before you can ask the same party leader to join again), but I've seen these options in other MMOs and it's extremely handy to have.