Business Rule is not supported in Now mobile To-do screen of HR tasks.

[shiva1997]

We have a business rule - 'AutopopulateHRBP Name', to automatically update HRBP in HR task. In ESC portal it's automatically populated through this ss rule. But not in now mobile, Here you can see in screenshot HRBP name need to manually update in now mobile screen(screenshot media (9)), but in portal it populated automatically( screenshot - hrbp).

[wojasso]

Now Mobile’s To‑Do forms don’t load the legacy browser UI, so g_form client scripts or on‑load business rules from the Employee Center won’t run. They render offline layouts and call the REST API directly. This is why your AutopopulateHRBP Name logic works in the portal but the HRBP field is blank in the mobile task.

To populate a field in the mobile experience you have a couple of options:

• Move the logic to a before/after Business Rule on the task table rather than relying on a UI policy. A rule that runs on insert (or insert/update) and sets current.hrbp based on the parent case/request will run regardless of the channel. Mobile will download the updated record after save.
• Alternatively, use a default value in the mobile data item. In the Now Mobile app builder you can edit the To‑Do form, select the HRBP field and set a “Default value from another field” or call a script action to return the value. This runs client‑side in the mobile app.
• If you need real‑time updates before the record is saved, create a Mobile Script action for the form that calls a Script Include/REST API to compute the HRBP and writes it back to the view model.

In summary, your existing rule probably uses browser APIs and doesn’t execute in mobile. Move the population logic to a server‑side business rule or mobile script so that the HRBP field is populated for both portal and mobile users.