Example:

spec:
  topology:
    rules:
      components:
        # **Optional**
        #
        # CN deployment rules, also divided into CN nodes by group
        cn:
          - name: zone-a
            # Valid values: numbers, percentages, (0, 1] fractions, not filling in will mean the remaining replica (only one can be left blank)
            # The sum cannot exceed .topology.nodes.cn.replicas
            replicas: 1
            selector:
              reference: zone-a
          - name: zone-b
            replicas: 1 / 3
            selector:
              reference: zone-b
          - name: zone-c
            replicas: 34%
            selector:
              reference: zone-c