How to impliment subscribe and publish working seperatly in same cpp file [closed]

I am not much familiar with mqtt and am doing an R&D work on the same; How do i run a mosquitto_subscribe() seperate and publish messages seperatly ; ie susbcribed topics will be processed in 5 min interval and messages will be published in 1 sec interval ; The subscriber will be subscribing to seperate topic published from another application, and I am using libmosquitto .