Can I create a user role which can only update data groups in BIG-IP LTM V12.1.2?
There is no role dedicated to Data Groups objects.
the best option available to you is iRule Manager role.
* can manage DATA GROUPS along with creating, editing and managing iRules
* have read access all other objects
* can limit access to specific partitions
Manual Chapter: User Roles
Thanks - that is a useful pointer!