I want to get the introduction about a Client adding subscription on behalf of client 2,do you know where introduced in the solace guide,thanks you
You are looking for subscription managers.
A subscription manager is a custom coded program running in the back end of your enterprise which manages subscriptions for other clients. Solace enables a centralized subscription management architecture by providing a special feature which allows certain clients to subscribe and unsubscribe to topics on behalf of other clients.
There's a couple of blog posts on the Solace website that describe this in detail.
An Architectural Look at Managed Subscriptions in Solace
Solace Managed Subscriptions in Action