voxel_grid filter in all dimensions

edit

I know it is probably late for you, but might be useful for someone else: we can create a launchfile with multiple voxelgrid nodelets like this:

<launch>
<node pkg="nodelet" type="nodelet" name="pcl_manager" args="manager" output="screen" />
<!-- Run a VoxelGrid filter to clean NaNs and downsample the data -->
  <node pkg="nodelet" type="nodelet" name="voxel_grid" args="load pcl/VoxelGrid pcl_manager" output="screen">
   <remap from="~input" to="/velodyne_points" />
    <rosparam>
      filter_field_name: y
      filter_limit_min: 0
      filter_limit_max: 17
      filter_limit_negative: False
      leaf_size: 0.05
    </rosparam>
   </node>
   <node pkg="nodelet" type="nodelet" name="voxel_grid2" args="load pcl/VoxelGrid pcl_manager" output="screen">
   <remap from="~input" to="/voxel_grid/output" />
   <remap from="~output" to="/Filtered_Lidar" />
    <rosparam>
      filter_field_name: x
      filter_limit_min: -7
      filter_limit_max: +7
      filter_limit_negative: False
    </rosparam>
  </node>
</launch>

Note that they have different names, and the output of the first is remapped to the input of the second. Hope it helps!