I am using ActionBarSherlock and want a similiar functionality of the home button as it is known by Google Maps.
You cannot access the home view because it exists above the content view and in the window decoration.
Google uses a custom action bar on pre-Honeycomb devices which exists inside the content view. This is what allows them to make this custom dropdown. On Honeycomb and newer they use a highly customized version of list navigation in the system action bar.
Since you are using ActionBarSherlock you have two options: