Grouping facet listed items

Tried to find anything on the issue but maybe my terminology on the subject sucks.

Lets say we have a facet as follows:

Facet
- Facet link 1
- Facet link 2
- Facet link 3
- Facet link 4
- Facet link 5
- Facet link 6
- Facet link 7

I am trying to do this:

Facet
- Facet link A
- Facet link B
- Facet link C

Where,
selecting "Facet link A" would present the results that "Facet link 1", "Facet link 2" and "Facet link 3" would present
selecting "Facet link B" would present the results that "Facet link 4" and "Facet link 5" would present
selecting "Facet link B" would present the results that "Facet link 6" and "Facet link 7" would present

Sorry if this is issue is a duplicate but I cculd not locate it.