The way you'd accomplish this is through the deployment levels of the package. By default, Robot Manager has three deployment levels (DL); Development, UAT, and Production. You may edit, delete, and add to these as needed. Each DL can be assigned a different version of a given package. Typically, when you want to assign a package, you do it to a given "group" in your hierarchy. The hierarchy is determined by how you imported your users (or if you added them manually). For this, I would create a new group in the hierarchy and update these users so that they were members of this new hierarchy group. This way, users would have only a single assignment made to them. If the group is small enough, then you can leave their original assignment in-place and simply assign this version of the package to them individually. These users would then get a selection and would be able to select between the different versions they were assigned.

https://community.pega.com/knowledgebase/articles/pega-rpa/using-pega-robot-manager-842#packages