Manuel,
Thank you for the reply. I tried to do as shown in your link but just can't get it right.
Here's my simple attempt to convert {0:0} to {0} using ReplaceBranches, without any luck.
I tried different possibilties with separators but... not working.
in the image that you upload, the wing botton receiver has only one branch... ? if you want to convert {0:0} to {0} just use the simplify tree component... or try with the flatten tree component.