I'm not sure we have something for you, but you can do some simple hemispheric comparisons like this.

3dLRflip -prefix lrfunc func_slim+tlrc.
3dcalc -a func_slim+tlrc -b lrfunc+tlrc. -expr 'a-b' -prefix lr_asym

This method assumes the data is centered about an AC-PC line. The method is not cluster specific, but you could apply a mask to the result or in the 3dcalc command. For a related idea, see this link on separating left and right with 3dcalc:

[afni.nimh.nih.gov]

If you have two ROIs in a dataset with a value of 1 for the left ROI and a value of 2 for the right ROI, you could compare the asymetry of those two ROIs with these commands.

3dcalc -a lrrois+tlrc. -expr 'equals(a,1)' -prefix leftroi
3dcalc -a lrrois+tlrc. -expr 'equals(a,2)' -prefix rightroi
3dLRflip -prefix flippedrightroi rightroi+tlrc.
3dAllineate -cmass -warp shift_rotate -base leftroi+tlrc. \
-source flippedrightroi+tlrc. -prefix al_flipped -cost ls \
-source_mask leftroi+tlrc. -weight leftroi+tlrc.
3dcalc -a leftroi+tlrc. -b al_flipped+tlrc. -expr 'a-b' -prefix 'lrroi_asym'

In this method, left-right flipping creates a mirror image of the right ROI. Then aligning the flipped ROI over the left ROI matches the two ROIs better. Now doing the simple difference of the two ROIs shows the difference in overlap between the two.

Is there something fancier you might want to do?