Hi sandhya,
In the overview page when the no.of buttons are more than the returning value of the method GET_NUMBER_OF_VISIBLE_BUTTONS then those buttons will be displayed under MORE.
So basing on the no.of buttons that u want them directly on the overview page u can pass that count in this method.
This method will be under TOOLBAR RELATED METHODS or u can find it in your view impl class.
Thanks and Regards,
DP.