(a) An arrangement between the associations for two or more common interest communities to share the costs of real estate taxes, insurance premiums, services, maintenance or improvements of real estate, or other activities specified in their arrangement or declarations does not create a separate common interest community.
(b) An arrangement between an association and the owner of real estate that is not part of a common interest community to share the costs of real estate taxes, insurance premiums, services, maintenance or improvements of real estate, or other activities specified in their arrangement does not create a separate common interest community. However, assessments against the units in the common interest community required by the arrangement must be included in the periodic budget for the common interest community, and the arrangement must be disclosed in all public offering statements and resale certificates required by this title.