REGIONS
seas, island groups, regions/islands & city (states)
above/to the left is a redraw of this map. from the Classical era on Reddit by Alexxii. The map actually shows the subregions of the main 6 regions of the Ancient Greek world, not the regions.
There are more subregions but I guess they were left out from the map to make it less busy. You can find more regions of Ancient Greece on Wikipedia since I only cover the ones provided on the original map.
Central Greece
Includes Attica, Boeotica, Euboea, Phocis, Doris, Malis, Locris, Aetolia and Acarnania
Peloponnese
Includes Elis, Achaea, Arcadia, Argolis, Laconia and Messenia
Asia
Includes Mysia and Ionia
Other regions
Thessalia/Thessaly, Epirus, Macedonia are all relatively unified. Again, you can find subregions within these regions using the Wikipedia link if you so wish.