Unfortunately at the moment were in a void per se, when it comes to group based rank up activities. Guildleves are where they should be, and there are even talks about increasing the timer beyond the 36 hour cool down.

Group content should be addressed in future patches, but I do remind you this is not a complete game in any sense of the word when it comes to content and daily activities, my advise is to take it easy with leves until everything is in place, you will enjoy it more later.