file1     file2
---------------------------------------
    x      x    /              
    x      x    /g1            
    x      x    /g1/dset1      
    x      x    /g1/dset2      
    x      x    /g1/dset4      
    x      x    /g2            

group  : </> and </>
0 differences found
group  : </g1> and </g1>
0 differences found
dataset: </g1/dset1> and </g1/dset1>
0 differences found
dataset: </g1/dset2> and </g1/dset2>
0 differences found
dataset: </g1/dset4> and </g1/dset4>
0 differences found
group  : </g2> and </g2>
0 differences found