Hi,
the option is not there in rtabmap-export. Modifying the code after
there you may add this to filter between 0 and 2 meters:
cloudToExport = util3d::passThrough(cloudToExport, "z", 0, 2);
cloudIToExport = util3d::passThrough(cloudIToExport, "z", 0, 2);
It could also be done on command line with the exported cloud if in PCD format with:
$ pcl_passthrough_filter inpu.pcd output.pcd -field z -min 0 -max 2
cheers,
Mathieu