Repeating group - removing duplicates based on one field

First off, sorry, I looked into the Forum but could not find a solution there.

The Data things structure:
GolfHoleMarker
Fields Types
CourseID : Golfcourse
Player ID: User
MarkerType: markertypes (option set)
Hole Number: Integer

Note: A golf hole marker is a GPS (LON/LAT) location on the golf course. For example, I can create one for the front of the green on hole no. 1; another one for marking where a lake starts, etc,… in my WebApp, I will be able to know how far I am currently from those markers.

The Repeating Group (RG) Do a Search statement:
What I need to do is to generate a RG that will contain all markers, minus those the current user already has, and remove those markers of duplicate MarkerType.

The search so far…
image
image

In the next screen capture, I show a duplicate type. The Front of Green is there twice. This happens because two players have added each a marker for Front of Green on hole number 1.

What I am not able to do, is to only show one Front of Green for hole no. 1; meaning only one type of marker per hole.

Thanks in advance.
Guy