How to use organization structure in Business Process?

Organization structure (users, functional and organization roles) are located in "System administration object". But what do you mean "route to sales department"?

Dear Nagaraju, 

You can do it using business process which will read data from "Users in Roles" object filtered by the needed role and then reading data from "System administration object" with filter applied to read only those records which id value matches User gathered from the previous Read Data element. 

In this way you will be able to use Modify Data element which will fill the owner field of the needed record with Contact value read from the previous process element. 

Please see the screenshot via this link: http://prntscr.com/qcjmp3

This is the simplest process which would allow you to assign newly created lead to someone who is in needed role. 

You can apply more filters or add other elements to make it more specific and precise. 

Please note that this process will always assign new lead to the same person, cause first element reads the first record of collection matching it's filter. 

Thus, the same user will always be read by this element. 

You need to extend the filter or use the script task in order to assign it to different users. 

Kind regards,

Roman