I do not think this is possible based on the fact that the group field is treated by ACF as a repeater field with one row. I could be wrong, I’m not the developer. To get his input on this you’d need to submit a support ticket here https://support.advancedcustomfields.com/new-ticket/
However, you can do this if you want to create a load field filter https://www.advancedcustomfields.com/resources/acf-load_field/. You can set the conditional logic of your field in this filter and it can include fields that ACF does not give you options for. In this case, since there will only be one of the fields you want the condition to be then it should work.
For an example of what the conditional logic setting for a feild looks like, create a field with conditional logic and export it to PHP. You can look at the field code and use that as a guide for adding custom conditions.
