Postgresql - Create role to connect to database and revoke all other permissions

I have an application which is configured with the multitenancy strategy of "single database multi schema". Now I want to create a role which can have only specific permission that is to : 1. connect to the database 2. should be able to switch role. Please help/guide me to create the as per the above requirement. No other object (like other schema, tables those schema) in the database should be visible for this role. So that I can use this role to login and based on the tenant I can switch to another role which can have access to a particular schema only .