I'm requesting a permission grouping feature like in GroupManager. This allows me to easily assign groups of permissions to certain players without giving a player a bunch of permission nodes. For example

globalgroups.yml

g:newgroup
- permission.node.one
- permission.node.two
- permission.node.three

default.yml

###Adds permission.node.one, permission.node.two, and permission.node.three to group default.
default:
- g:newgroup

If there is already a way to do this, I apologize for wasting your time. Thank you for helping me in advance.

Yes, this is possible.

There's no concept of a "global group" in LuckPerms, but any group can be "global".

Using your example above:

/lp creategroup newgroup
/lp group newgroup permission set permission.node.one true
/lp group newgroup permission set permission.node.two true
/lp group newgroup permission set permission.node.three true

/lp group default parent add newgroup

Hopefully that makes sense. 😄