Are you saying that you will create separate users for Branch Manager or OM at Branch to execute this process? How many branches do your bank have?
Yes, viewing alerts individually is difficult here. As routing is only possible at Entity level, you can't route individual alerts. You can propose users to take actions on all alerts except those where RMs / OMs feedback is required and then route it to them. Still, it will have conflicts as next day new alerts will be clubbed under same Entity.
I would propose to go with my previous comment that there is no Work Flow available in SAS AML system to reach out to Branch/RM. Compliance Analysts / Investigators have to reach out to Branch/RM for additional information through outlook / emails (i.e. outside SAS AML system).
I find, below approach difficult in terms of hardware sizing as well. Have you done hardware sizing, there is a question there for number of concurrent users as well. There you might face problem.