Hi Matthias,
Thank you for your interest in syncfusion products.
"Selecting all parents and parents-parents through client side can be done by recursively checking the parent nodes. Please refer the below code snippet to achieve this,
[JavaScript]
[ASPX]
Kindly refer the below documentation link to know more about this requirement.
http://help.syncfusion.com/ug_84/User%20Interface/ASP.NET/Tools/Documents/howtoautomaticallycheckparentnodewhenchildnodeischeckedanduncheckingchildnodeswhenparentnodeisunchecked.htmKindly let us know your concerns.
Regards,
Varalakshmi.R.S