I've posted this same coral some time ago, along with a bunch of other finds from the same locality, but it's identity is still bugging me. In my search, I've narrowed the potential genus down to either Cladocora or the montlivaltid Thecosmilia.
The locality is the Čerevićki potok fm., Serbia, Maastrichtean. In the Paleobiology Database, only Thecosmilia has been reported in the locality, but Cladocora was also apparently reported in the relative geographic vicinity.
View of the entire colony:
View of the entire colony(up close):
View of the corallites:
Album link: https://imgur.com/a/vtWMX
Here's the descriptions of both genera, from Corallosphere:
Cladocora
Thecosmilia
So, what's your judgment? Any help would be greatly appreciated.