Going to be hard for anyone to answer without more detail on how things are connected.
From the little you have provided you really have 2 separate issues. The first is how to make the internet connection talk together and the second how to combine work groups.
It is unclear if these are separate location and you want to use the internet to connect them of if they are at the same location and you want to share a internet connection.
Does not pay for me to guess and give a answer to a problem you do not have.
I have 5 different internet connection and have 5 different work-groups i want to connect all these connection in to a single domain ,how to set all these internet connection in to one i use dsl connection