You can either use a wireless repeater, or some other bridging technology such as powerline or MoCA (coax).
For wireless repeaters, it's primarily about placement. It may need to be in a stairwell, or near the top or bottom of the stairs. Difficult to give hard and fast rules since each home/office has its own challenges. You just need to try it and find out.
Powerline and MoCA offer the option to use the other wiring in your home/office as an ethernet network. And then use wire from those adapters to your devices, or to additional “localized” wireless APs.