If i am using Role Hierarchy and i want to give permission to particular lower level to access higher level.Is it Possible in salesforce?

Hi suraj,

You can achieve this with the help of Sharing Settings. Click Settings > Setup > Users & Control > Security Control > Data Sharing Settings.
In the Data Sharing Settings page, click Edit All Default Permissions.
In the Edit Default Organization Permissions page, update the following Access Privilege for modules:
> Private
> Public Read Only
> Public Read/Write/Delete

Thanks.