Company directory - Employees to view colleagues work phone numbers via Web-base and App

The limitation is specifically with the mobile Company Directory - it only shows personal phone numbers, not work ones.

There isn't currently a secure way for employees to access colleagues' work phone numbers. The only way to give access to work phone numbers is through elevated access rights, but this requires setting Contacts to "Update" - there's no view-only option. This means anyone with access can edit contact details, which creates the security risk.

Or consider work phone numbers visibility in Org Chart.