Multiple SLAs, custom fields and rules

Content

We use SLAs to determine the access levels of our agents for our CP internal knowledgebase. We want to do this when they login on the internal site. I see that SLAs can't be assigned by ConnectPHP and I read some posts about creating a custom field and then using rules to assign based on that.

Our SLAs are basically regional access levels, so there are a few agents who could have multiple SLAs. How does that work with custom fields and rules? Can I have a menu custom field that has multiple options selected? I don't usually do anything with custom fields or rules so this part is all new!