Dynamic On Call Calculated Roster

Hi Everyone,
I am building on call rosters at the database level, and then pulling the data with drop down selection components.

I have this part working correctly, but i am wanting to make the on call selection a bit more automated.
As of now, the primary on call person needs to be selected, and so does the second, third and fourth user (this is due to needing to call all users in the database at a certain escalation level)

I am wondering if anyone has an idea as to how i can just have the first on call user selected, then all other users who are not the first on call will be selected in the background?

Right now all users are individually selected from a drop down and that value is written to a memory tag, which is read in the alarm pipeline notification block calculated roster script. I then generate dictionaries with those values.

What i ended up doing is running a sql query to select all users who are not the primary on call, i then pull the strings out of each row, and write those values to my memory tags when the on call person is changed.