Hi Leonardo,
Thanks for using Syncfusion Products.
Yes,it is possible to Expand/Collapse sub-nodes in OrgChart diagram. We have prepared a simple sample to demonstrate this and the same can be downloaded from the below link.
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=ExpanderHide(OrgCharLayout)450169985.zipPlease let me know if you have any concerns,
Regards,
Bala Murugan A.S