I have two different UCM and I would that other two SES attend to the search requests for each of the repositories (eg, for SES_1 to UCM_1 and SES_2 to UCM_2. However, I would like to consolidate the results of research in a single list. In this case, I had a third SES to consolidate the results? Where can I get examples of how to do this?
Yes, this is very doable. SES provides a distributed ("federated") architecture for this purpose (see SES Admin guide for details). You can connect multiple SES into a distributed system where each of the connected SES serves up part of the content.
In your case, two SES instances might suffice (in the SES federation architecture a single SES can both crawl content and federate to another SES instance).