Manage decals display by groups

Hi,

Searched for an answer on google and could only find supposition in forums.

Is there a way to manage decals display by groups?

Best example : You want a unit selection decal to apply on floor and nothing else, but you’ll want a blood splatter to apply on everything, is that possible?
Only option i know right know is to exclude a mesh from ALL decals. But maybe what i want do should be done another way than decals.

Thanks.

Thomas