I've been going back and forth between Houdini and C4D this the past week. Houdini exports groups without any special settings. When you import to Cinema 4D, the groups become polygon selection sets. So learn Houdini groups. The simplest way is to lay down a Group Sop and enable the 'bounding region' setting, then inclosing part of your geo in a box/sphere/etc.
Also, Houdini attributes become Cinema 4D vertex maps, at least some of them. I haven't checked lately. The nice thing about the attributes as vertex maps is that you can bring those into a Redshift shader network. Generally, you're going to want to optimize your attributes and groups (attribute delete / group delete) prior to writing out to alembic, as with any Houdini scene file. Each attribute is costly for processing and storage as well.