Hi John,
Thanks for using Syncfusion Products.
You can select multiple nodes when we drag the mouse as a marquee. Please try the below attached sample and let me know if this works.
MutipleNodeSelect-428812495.zipAnd also you can select multiple modes with Control Key +Click
Note: You can able to select multiple nodes only when the nodes EditStyle.AllowSelect property is true.
Please let me know concerns.
Regards,
Bala Murugan A.S