As of the current release for Minecraft Bedrock Edition, villagers that are below thier work stations and beds will pathfind towards the X and Z coordinates of thier workstations and beds but won't attempt to travel up the stairs as seen in the picture below. 

Steps to replicate:

Build a platform several blocks above the ground build the platform to be at least 12 blocks long and 4 blocks wide (this is just to match the size of the platform shown in the image)

Place a bed and a workstation on one end of the platform.

Build a staricase that leads from the ground to the platfrom on the other end of the platform.

Spawn in a villager on the ground below thier bed & workstation on the platform.

Set the time to night, or ring a bell once the villager has linked to the bed and workstation.

Then, the villager will just stand below thier bed thinking that they're in the right spot.

Expected Result:

The villager should walk over to the other end of the platform to walk up the staircase, then travel to thier bed & workstation.