Default GPO permissions

full access of group policy

• domain admin
• enterprise admin
• creator owner - same level as domain admin but within delegated scope
• local system

read/apply : authenticated users

grant additional permissions

• create : add to GP creator/owner or GPMC permissions
• editL r./w via GPMC
• link mgmt: delegation in GPMC or DOCW (right-click OU for delegation wizard)
• modeling/results: delegation in GPMC or DOCW

Group policy Creator Owner - allows access to all GP in domain or narrow it down to OU level

Granting GPO permissions via GPMC 

delegation tab limited in only link GPO and modeling/analysis.

but Advanced option allows for granular permissions for GPOs.