For much of your work with regions, STAR-CCM+ opens a dialog like this one. It allows selection of multiple regions.
Regions list box - a list of all the regions of the mesh that have not been selected.
Selected list box - a list of the regions that have been selected.
>> - Transfers all items in the Regions list box from there to the Selected list box.
> - Transfers the item that you select in the Regions list box from there to the Selected list box.
< - Transfers the item that you select in the Selected list box from there to the Regions list box.
<< - Transfers all items in the Selected list box from there to the Regions list box.
Apply - Passes the list of selected regions to the function that triggered this action.