You can go in 2 ways
1. You can board bus from patiala for sangrur nd in sangrur u have to de broad from bus in barnala kainchian from where u can get direct bus to dhuri (any ludhiana bound bus will go to dhuri) or u can also de board at bahawnigarh from where u can get direct bus to dhuri but the bhawnigarh-dhuri route us full of villages nd u may get confused so better is to go sangrur.
2.you can take an direct train from patiala to dhuri.