You can see the Zone a Bee can reach displayed in the upper left corner of each Bee when sending Bees on Missions.
The Zone that your Generations Working Bees can reach is determined by its Endurance stat.
Training Bees reach is based on the player's XP level.
Genesis Bees can travel to all eight Zones in Universe one.
Use the Filter to sort by Endurance to group your Bees by Zone.