Hi Ryan,
Thank you for your question.
Please refer to the following Help Article:
RadMultiColumnComboBox - Overview. As you can read there, you need the
EditorControl property which gives you the reference to the RadGridView in the dropdown.
Since the selection in RadMultiColumnComboBox is related to the CurrentRow of RadGridView, you can get a cell value by the
CurrentRow property:
I hope this helps. If you have additional questions, feel free to contact me.
All the best,
Nikolay
the Telerik team