Yes. For components within components, you expose the interfaces through delegation connectors (ports) on the outer component.
This is the second use case for components in BridgePoint, building systems. Components can represent systems or subsystems (note: not xtUML subsystems, as explained in my previous response). The subsystems can either be domains, or have other subsystems nested in them. This use case is purely architectural, so outside of the xtUML modeling domain.