Are the text field and group box in a data view? If they are, you can add a boolean attribute to your entity, and set the condtional visibility of the group box and text field to be visible on that attribute. Then you can use a microflow button to run a microflow that uses the change activity to set the boolean value (don't forget to use refresh in content).
If the text box and group box aren't in a dataview, you can create a non-persistent entity with a boolean attribute and use that.
Hope this helps!
How can i use Check box with multiple select By Using Enumiration
Just adding my bit – I suggest using a Nanoflow instead of a Microflow to toggle the boolean attribute responsible for showing/hiding the fields. Fewer calls on the Mendix cloud like that, and quicker ux.