How can we add Cities in Geography Hierarchy

Summary:

Usually we have public holidays by country (Canada) or at the province level e.g. Alberta, Quebec etc. Our client has a requirement on some Public holidays is to be observed at City level.

We are creating Geography hierarchy and want to know how to add City under the province node.

under "Geographic Tree Territory Code Data Source" all we see is countries.

also under "Geographic Tree Calendar Event Data Source" we only see States and Provinces

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