Can a server act as a primary server and replica?

What are you wanting to replicate? Are you replicating AD? Or Files? Are you trying to have backups from the computer stored on the Primary Domain Controller?

You need to give more information.

"I have in the branch office a PC which I want to replicate to the main office..."
I'm not sure what you're asking here.  You want to duplicate the PC to a different site?  Or some content on that PC?

Is this for backups?  Or do you want people to access the replicated PC/data?  Do you want data in both places to be editable and synchronized?

Currently, I do a Hyper-V replica using Hyper-V replication from the main office to the branch office (the branch office server is acting as a replica server) on all servers/PC that are in the main office for failover in case the main office is down. In addition, the AD is being replicated by creating two sites in AD and the AD in the branch office serves the AD for the computers in the branch office.

My question one Hyper-V PC that is the branch office, I would like to replicate using Hyper-V replication to the main office, is this possible? Can a server act as a primary server and replica?

I would prefer if I can have the data in both places to be editable and synchronized, so I can use this PC in any location regardless if it is up in the primary location (hyper-v replica will not allow to turn on a replica if it is up the primary site) but I think there is not a way to make this work.

Thank you