In Maya you have ‘Separate’ and ‘Extract’ for Specific sections of polygons you want to separate.
In Cinema you have ‘Split’ and ‘Disconnect’ both of which are useless - Split just duplicates your selection
and Disconnect just temporarily separates a section without being able to create a new object !!?
I know Cinema is not the best for polygon modelling but this is such a rudimentary thing you need often …