Yes, this scenario is supported. Please refer to Multiple Domains.
Source: https://learn.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-faq
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Does Azure AD Connect support syncing from two domains to an Azure AD?
Source: https://learn.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-faq
Yes, this scenario is supported. Please refer to Multiple Domains.
Source: https://learn.microsoft.com/en-us/azure/active-directory/hybrid/reference-connect-faq
You can also refer https://learn.microsoft.com/en-us/azure/active-directory/hybrid/plan-connect-topologies#multiple-forests-single-azure-ad-tenant for a more detailed information on the AD Connect topology.