region-add-devices rUK \ of:0000000000000001 \ of:0000000000000002 \ of:0000000000000003
The currently configured regions can be listed with the regions command:
onos> regions id=rDE, name=Germany, type=COUNTRY master=[localhost] of:0000000000000013 of:0000000000000014 of:0000000000000015 of:0000000000000016 of:0000000000000017 id=rES, name=Spain, type=COUNTRY master=[localhost] of:0000000000000018 ...
Note that regions do not have any notion of hierarchy; they are simply "collections of devices". The hierarchy is expressed using Layouts.