How to express this architecture

Hi,

There are several models, an instance of one model can own (be an
owner) another instance (that is a possession, property) of the same
or another model. How to express this architecture, so that I can
easily access to all owners or all properties of exact model of some
instance:

an_instance.owners.owners_only_with_some_model
an_instance.properties.properties_only_with_some_model

or

an_instance.owners_only_with_some_model
an_instance.properties_only_with_some_model

And it'd be great if both owners_only_with_some_model and
properties_only_with_some_model were proxies.

Thanks.