David Musgrave the Microsoft Dynamics GP Specialist proofed that the GP could have Row Level Security customized by developing the tool for the sample company, the tool is great and contains all what we need to filter GP rows.
You can find this tool under the following link:
But unfortunately the tool is still proof of concept, and not officially released, lets hope to have it one day as one of GP modules!
Mohammad R. Daoud
MCP, MCBMSP, MCTS, MCBMSS
Software Development Manager
+962 - 79 - 999 65 85