How to Keep the maximum boundary

[lizhipeng1987324]

I need your help thank you .

How to delete small boundaries within different regional boundaries

Only retain the largest boundary within each region?

[lizhipeng1987324]

How to use macros to keep only the selected yellow boundary in the attached image and automatically delete the small boundary inside? Thank you

[lizhipeng1987324]

The boundary before running the macro is in an unselected stateThe boundary before running the macro is in an unselected state