Simplified path. The puzzle showed the main steps; the full route is being checked.
Greek
mētēr‘mother’
polis‘city’
combined
combined
English
metropolis
‘A major city or principal urban centre.’
The story of metropolis
Metropolis comes through Latin from Greek mētropolis. Its components mean mother and city. The expression supplies an older relationship behind a modern word we often understand simply as a very large urban place.
This view explains the components. They are pieces of one construction, not consecutive borrowing stages.