Hey Sandro,
When performing multiselect filtering in Datagrid2, if you want to select multiple default values, you should express them as comma-separated. I’m sharing an example below, I hope it helps.
Hi Sandro Rüssel
Refer this widget it's helps you :
https://marketplace.mendix.com/link/component/210904
BOOT STRAP MULTI SELECT widget:
https://marketplace.mendix.com/link/component/2295
https://community.mendix.com/link/space/widgets/questions/114481