The Pods 3.0 release originally planned that you may have found details on that included that feature has been split up into Pods 2.8, 2.9, and 3.0 — with 2.8 including field groups and 2.9 including simple repeatable fields.
The 2.9 and 3.0 releases have had their major feature voted on by our Friends of Pods (donors).
3.0 is in development now and should be in beta in the next week or two. That 3.0 feature will be Conditional Logic for Fields.
Currently the work to support repeatable field groups is a high level of work and has not been voted forward yet.
But Pods has had a feature since 2.7 that may fit your needs and is better for structured content: Flexible Relationships —