You use one Roon Server in your home. You can then have this Roon Server stream to any number of systems on the same (home) network, and you can control it with any number of control/remote devices.
One Roon license can be used on one Roon Server at any one time. You can use more than one Roon Server (e.g. at the office) but you have to switch the license between them. I.e., can’t use the two servers at the same time. And the databases on the two servers will be separate unless you transfer it manually.
You could, however, use Roon ARC in the office and have it connect to the Roon Server at home.