Hi Shannon,
This sounds like you need some additional code logic to modify the example script from that referenced article. The way I would approach this would be to modify the if (isManager()) portion of the code so that:
if the user is a manager:
- display a drop down of salespeople names to select
- set user == selected name
return(salesData[salesData$salesperson == user(),])
This will let the manager impersonate the salesperson for viewing the data.