AD Connect - 2 AD Forests with 1 AD Connect server
Video on syncing two separate Active Directory forests to one Azure AD tenant with a single AD Connect server, including the DNS forwarding between them.
Set Up an External Trust Between Two AD Domains
Video on creating an external trust between two separate Active Directory domains on Server 2022 so users from each side can reach the other's resources.
Server 2022 - CodeTwo - Active Directory Photos
Video on using the free CodeTwo Active Directory Photos tool to manage user profile photos in Active Directory and sync them to Azure AD.