With BOINC Manager in advanced view  it is possible to control a remote client in a local area network, same as were it the local client. If properly configured having set up the remote_hosts.cfg file, the only thing needed is opening the Advanced menu's "Select computer..." option, fill in device name or pick from drop down list and, when not auto-filling with asterisks, type the password as stored in the remote client's gui_rpc_auth.cfg file.
Switching back to the local client does not require any entries. Simply leave both fields blank.
How to set up the clients on for remote control is covered in an article of the (Official) BOINC wiki article: Controlling BOINC remotely