Multiples schemas

Hi,
Is there a way to construct a multi schema in my data base?Something like: mysystem.finances.money.tables
mysystem.finances.money.functionsmysystem.finances.credits.tables mysystem.finances.credits.functions
mysystem.amount.products..........
 

Or can I use another database like:createdb DB1createdb DB2psql DB1select * from DB2.schema.table

Or i need to construct the tables in the same database and the same schema
like:mysystemdb.amount.productsmysystemdb.amount.vendorsmysystemdb.amount.clientsmysystemdb.finances.money....

Could I create a multi schema into another schema ??? or is there only one level
for schema sctructs?

Thanks for all