Thanks everyone for the replies, I feel my question was not clear
I have only one captive portal, i dont hav captive portal based on location
When my guest comes to IT department, the guest select IT department from the dropdown in the captive portal, When the department is selected, sponsors for IT will be visible
When my guest comes to Mech department, the guest select Mech Department, and the sponsor for that department is visible
I could achieve this with attached method