well, if there is a view or stored procedure that references a different database or a linked server, you can query for that.
take a look at the view sys.sql_expression_dependencies, and pay attention to these columns:
referenced_server_name
referenced_database_name
referenced_schema_name
referenced_entity_name
you may need to do that in each of your databases, since you are trying to discover dependancies,a dn they are "saved" local to each database.
select *
from sys.sql_expression_dependencies
Lowell