diff --git a/doc/grid_radius_search.md b/doc/grid_radius_search.md
index 09b385b..cd62bd5 100755
--- a/doc/grid_radius_search.md
+++ b/doc/grid_radius_search.md
@@ -43,3 +43,9 @@ Options
 
 **output_name_attribut**: The name of the new attribut. [Default: radius]
 
+**3d_search**: Search in 3d (as a ball). [Default: false]
+
+**2d_search_above**: If 3d_search is false, take points only if exists points between the referent point and a distance above. [Default: 0.]
+
+**2d_search_bellow**: If 3d_search is false, take points only if exists points between the referent point and a distance bellow. [Default: 0.]
+
diff --git a/src/filter_radius_search/radius_searchFilter.cpp b/src/filter_radius_search/radius_searchFilter.cpp
index 82fb455..4566181 100644
--- a/src/filter_radius_search/radius_searchFilter.cpp
+++ b/src/filter_radius_search/radius_searchFilter.cpp
@@ -37,6 +37,8 @@ void RadiusSearchFilter::addArgs(ProgramArgs& args)
     args.add("radius", "Distance of neighbors to consult", m_args->m_radius, 1.);
     args.add("output_name_attribute", "Name of the added attribut", m_args->m_nameAddAttribute, "radius" );
     args.add("3d_search", "Search in 3d", m_args->search3d, false );
+    args.add("2d_search_above", "if search in 2d : filter point above the distance", m_args->m_search_bellow, 0. );
+    args.add("2d_search_bellow", "if search in 2d : filter point bellow the distance", m_args->m_search_above, 0. );
 }
 
 void RadiusSearchFilter::addDimensions(PointLayoutPtr layout)
@@ -68,7 +70,7 @@ void RadiusSearchFilter::ready(PointTableRef)
 
 void RadiusSearchFilter::doOneNoDomain(PointRef &point)
 {
-    // build3dIndex and build2dIndex are buuild once
+    // build3dIndex and build2dIndex are build once
     PointIdList iNeighbors;
     if (m_args->search3d) iNeighbors = refView->build3dIndex().radius(point, m_args->m_radius);
     else iNeighbors = refView->build2dIndex().radius(point, m_args->m_radius);
@@ -76,6 +78,22 @@ void RadiusSearchFilter::doOneNoDomain(PointRef &point)
     if (iNeighbors.size() == 0)
         return;
     
+    if (!m_args->search3d)
+    {
+        double Zref = point.getFieldAs<double>(Dimension::Id::Z);
+        if (m_args->m_search_bellow>0 || m_args->m_search_above>0)
+        {
+            bool take (false);
+            for (PointId ptId : iNeighbors)
+            {
+                double Zpt = refView->point(ptId).getFieldAs<double>(Dimension::Id::Z);
+                if (m_args->m_search_bellow>0 && Zpt>Zref && (Zpt-Zref)<m_args->m_search_bellow) {take=true; break;}
+                if (m_args->m_search_above>0 && Zpt<Zref && (Zref-Zpt)<m_args->m_search_above) {take=true; break;}
+            }
+            if (!take) return;
+        }
+    }
+    
     m_args->m_ptsToUpdate.push_back(point.pointId());
 }
 
diff --git a/src/filter_radius_search/radius_searchFilter.hpp b/src/filter_radius_search/radius_searchFilter.hpp
index 515c155..3a4346e 100644
--- a/src/filter_radius_search/radius_searchFilter.hpp
+++ b/src/filter_radius_search/radius_searchFilter.hpp
@@ -32,6 +32,7 @@ class PDAL_DLL RadiusSearchFilter : public Filter
         Dimension::Id m_dim;
         bool search3d;
         Dimension::Id m_dim_ref, m_dim_src;
+        double m_search_bellow, m_search_above;
     };
     std::unique_ptr<RadiusSearchArgs> m_args;
     PointViewPtr refView;
diff --git a/test/test_radius_search.py b/test/test_radius_search.py
index 2e077e2..cb35c0d 100755
--- a/test/test_radius_search.py
+++ b/test/test_radius_search.py
@@ -35,6 +35,7 @@ def distance3d(pt1, pt2):
     nb_points = randint(10, 20)
     nb_points_take_2d = 0
     nb_points_take_3d = 0
+    nb_points_take_2d_above_bellow = 0
 
     for i in range(nb_points):
         pti_x = pt_x + rand.uniform(-1.5, 1.5)
@@ -51,6 +52,10 @@ def distance3d(pt1, pt2):
 
         if distance_i_2d < distance_radius:
             nb_points_take_2d += 1
+            if pti_z>pt_z and pti_z-pt_z>0.5:
+                nb_points_take_2d_above_bellow += 1
+            if pti_z<pt_z and pt_z-pti_z>0.5:
+                nb_points_take_2d_above_bellow += 1
         if distance_i_3d < distance_radius:
             nb_points_take_3d += 1
 
@@ -86,7 +91,17 @@ def distance3d(pt1, pt2):
             "src_domain": "SRS_DOMAIN",
             "reference_domain": "REF_DOMAIN",
             "output_name_attribute": "radius_2D",
-            "3d_search":False
+            "3d_search":False,
+        },
+        {
+            "type": filter,
+            "radius": "1.",
+            "src_domain": "SRS_DOMAIN",
+            "reference_domain": "REF_DOMAIN",
+            "output_name_attribute": "radius_2D_above_bellow",
+            "3d_search": False,
+            "2d_search_above": 0.5,
+            "2d_search_bellow": 0.5,
         },
         {
             "type": filter,
@@ -107,11 +122,15 @@ def distance3d(pt1, pt2):
 
     nb_pts_radius_2d = 0
     nb_pts_radius_3d = 0
+    nb_pts_radius_2d_above_bellow = 0
     for pt in array:
+        if pt["radius_2D_above_bellow"] > 0:
+            nb_pts_radius_2d_above_bellow += 1
         if pt["radius_2D"] > 0:
             nb_pts_radius_2d += 1
         if pt["radius_3D"] > 0:
              nb_pts_radius_3d += 1
 
     assert nb_pts_radius_2d == nb_points_take_2d
-    assert nb_pts_radius_3d == nb_points_take_3d
\ No newline at end of file
+    assert nb_pts_radius_3d == nb_points_take_3d
+    assert nb_pts_radius_2d_above_bellow == nb_points_take_2d_above_bellow
\ No newline at end of file