You can derived your widgets from WBP_ODK_Widget. The InputMappingContexts property WBP_ODK_Widget can be used to configure which IMCs should be active when the widget is on screen. This will use the BPC_ODK_InputComponent to push a new IMC state onto the stack when the widget is displayed on screen. When the widget is closed, the state will be removed enabling whatever IMCs where active before the widget was opened.