How do I join my friend's guild? [XBOX]

My friend told me (offline) to join his guild, but I can’t figure out how to do that from the game. If I go to Guilds, my only options are to create a new one or to search. If I press “Y”, I can change the search settings to search for guild styles (competitive, coordinated, or friendly), but I don’t see anywhere to search for either my friend or his “referral code”.

Am I completely missing it? Or is there something else that needs to happen for me to join him?

The easiest way to join your friend’s guild is for either him or someone else from his guild to invite you.
Assuming your friend has a high enough guild rank and there are spots available, he just has to go here:

And enter your referral, or invite code.

That worked. Thank you very much, I appreciate the help.